
(lass __^ 
Uk_I__i 



PRESEXTCD BY 



BY ALBERT F. BLAISDELL, M. D. 



BLAISDELL'S REVISED SERIES OF PHYSIOLOGIES. 



Cbilo's JScch of "fcealtb. 

In Easy Lessons for Primary Grades. An Intro- 
duction to the Study of Physiology. Fully 
Illustrated. Price for introduction . . 30 as. 

Dow to fceep tctell. 

A Text-Book of Health for use in the Lower 
Grades of Schools, with special reference to 
the Effects of Alcoholic Drinks. Tobacco, and 
other Narcotics on the Bodily Life. Fully 
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Our Bootes ano 1bo\v XUe Xire. 

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t)o\v to Ceacb pb^siologs. 

A Handbook for Teachers. Paper. Fully illustrated. 
Price 10 cents. 



GINN & COMPANY, Publishers. 



OUR BODIES 



AND 



HOW WE LIVE 



AN ELEMENTARY TEXT-BOOK OF PHYSIOLOGY AND HYGIENE FOR 

USE IN SCHOOLS WITH SPECIAL REFERENCE TO THE 

EFFECTS OF ALCOHOLIC DRINKS, TOBACCO 

AND OTHER NARCOTICS ON 

THE BODILY LIFE 



BY 

ALBERT F. BLAISDELL, M.D. 

AUTHOR OF "HOW TO KEEP WELL " "CHILD'S BOOK OF HEALTH," ETC., ETC 



REVISED EDITION, 



BOSTON, U.S.A. 

GINN & COMPANY, PUBLISHERS 

1896 



r-7 III A_-"Z : It! ^ .-.-._• _ 



E ■ : . " . ' .-.'.' : .:::-.: . 



Z-: Xrr :-£--- p-r:?- 



PREFACE 

REVISED EDITION 



It has been the aim of the author in making this 
text-book, for the use of common schools, to present 
clearly and tersely the most important and interesting 
facts concerning our bodily life. To keep any machine 
in good running-order, we must know something of the 
structure and use of its various parts. So when we 
come to the study of this wonderful and complex 
machine, the human body, we must master such facts 
of its anatomy and physiology as are essential to a 
proper understanding of the simple laws of health. 

The real object of studying physiology in schools is 
to teach young folks how to keep well and strong, and 
to avoid evil habits that destroy character as well as 
health. Hence, special emphasis has been laid upon 
such points as have a bearing upon our personal health. 

It is now generally admitted that actual observation 
and actual experiment are as necessary in the study 
of elementary physiology as in any other branch of 
science. We must handle the skeleton itself if we wish 



IV PREFACE 

to get a fair idea of its bones. We must examine a 
drop of blood under the microscope if we would know 
how blood looks. Hence, as supplementary to the 
text itself, we have added a series of practical experi- 
ments. Most of them are simple, and require only a 
little painstaking and an inexpensive apparatus to do 
successfully. These experiments should be actually 
performed, and not merely read as a part of the text. 

This book has been thoroughly revised. New sec- 
tions and new chapters have been added, while others 
have been rewritten and rearranged. The new chap- 
ter on Physical Exercise, supplemented by a series of 
gymnastic exercises, will prove an attractive feature 
to those who realize the importance of physical culture 
to our young folks. 

The author has aimed to make everything plain by 
using a simple and homely style of writing. 

In the preparation of this revised and enlarged 
edition, the author and publishers are under deep 
obligations to Mrs. Mary H. Hunt, the Superintend- 
ent of the Department of Scientific Instruction of the 
National Woman's Christian Temperance Union, who 
has carefully revised the book. 

Albert F. Blaisdell. 

June, 1892. 



CONTENTS 



CHAPTER I 
Introduction ' i 

CHAPTER II 
The Bony Framework • 13 

CHAPTER III 
The Muscles . ........ 42 

CHAPTER IV 

Physical Exercise . 56 

t 

CHAPTER V 
Food and Drink 70 

CHAPTER VI 
Origin and Nature of Fermented Drinks . . . 81 

CHAPTER VII 
Digestion 92 

CHAPTER VIII 
The Blood and Its Circulation 122 

CHAPTER IX 
Breathing 142 

V 



VI CONTENTS 

CHAPTER X PAGE 

How Our Bodies are covered 161 

CHAPTER XI 
The Nervous System 177 

CHAPTER XII 
The Special Senses 210 

CHAPTER XIII 
Excretion 235 

CHAPTER XIV 
The Throat and Voice 243 

CHAPTER XV 
Simple Matters of Every-day Health. — What to do, 

and How to do It 249 

CHAPTER XVI 

Practical Experiments * . 280 

Review Analysis 329 

Text Questions for Review 331 

Notes 355 

Appendix 375 

Glossary 391 

Index „ 405 



OUR BODIES 



CHAPTER I 

INTRODUCTION 

i. Animal Life. — We need not be told that we have 
bodies made of flesh and bone, whose substance we see 
and handle every day of our life. Even a child knows 
that certain parts of his body, as the walls of his chest, 
and his heart that he feels beating within it, are always 
moving of themselves. 

We can move of our own free will from one place to 
another. The wind may rustle the leaves, and a breeze 
may sway a strong oak ; but the leaves and the oak 
have no power to move of themselves. We need not 
wait, like the trees of the forest, for the wind to blow 
us to and fro, or, like the pebbles by the roadside, for 
some one to stir us. Like the horse, dog, bird, or any 
other animal that has life, we can move from place to 
place. 

Every living animal, from ourselves down to the 
tiniest creature that lives its brief life in a single day, 
and that cannot be seen without the aid of the micro- 
scope, has the power to move of itself. 

Again, every child must see for himself that he is 
warm. Even in the coldest day of midwinter, let the 
stones and trees be as cold as the winter wind, our 



2 YOUNG FOLKS PHYSIOLOGY 

bodies, except perhaps the tips of the fingers and toes, 
are always warm. The horse, dog, and even the birds 
and the bees, are warm. All animals, in fact, are more 
or less warm as long as they are alive. 

2. The Body compared to a Locomotive. — Our 
bodies are in some rc5:e;:s very much like the locomo- 
tive. The bones and muscles answer to the machinery 
of the engine, and the motive-power is produced by the 
food we eat. We put fuel into the furnace. The water 
in the boiler is heated and expands into steam. Then 
the piston begins to work to and fro ; this moves the 
wheels, joints, and levers : and so the whole engine is 
set going by the fuel which is put into the furnace. 

Now, just the same thing occurs in our bodies. We 
take food, and that food passes into the stomach. By 
reason of that food, we are kept warm, muscular force 
is developed, and the levers and joints within us are 
set working, as we see in the locomotive. 

There is, however, an important difference between 
the two. The locomotive is all the time wearing: 

o 

itself out. It must be stopped, taken to pieces, and 
repaired by the machinist. So our bodies are all the 
time wearing out, but they are constantly repairing 
themselves. We take food, not only to warm us, but 
also for the building-up and repairing of our bodies. 
Remember, then, that the body far surpasses the engine 
in the perfection of its mechanism, inasmuch as it is 
self-repairing. 

3. The Body and its Nervous System. — If we 
exert our will, or " make up our mind " as we call it, to 
cross the room, to write with a pen, to pick a flower, to 



INTRODUCTION 3 

eat an apple, or to repeat some familiar maxim, we can 
do it. The mind, or brain, wills to do this or that 
thing. It sends out its order by the tiny, white, thread- 
like cords called nerves ; and the muscles are put in 
motion to do whatever the brain has willed them to do. 

Every child must have noticed, that when he pricks 
his fingers with a needle, touches a hot stove, or has 
eaten some unwholesome food, like an unripe apple, 
pain is produced. These same silvery-white cords, like 
telegraph-wires, carry special despatches to the central 
station ; that is, the brain : and the feeling of pain is 
there made known. 

This is the way every part of our bodies is watched 
over and protected. If it were not so, we should be 
continually hurting ourselves. This mind, which feels, 
and thinks, but which we cannot see, forms the essen- 
tial part of our being. It is the power to feel, to know, 
to think, to reason, and to will, that makes us what we 
are. Our bodies are ever busy. We eat, drink, and 
sleep. We move about, and are warm. We feel, hear, 
see, talk, breathe, and think. We do not wonder about 
it, simply because it is so common. 

When we do stop to think about it, how wonderful it 
is simply to be alive ! What study could be more 
important, interesting, and even fascinating, than that 
which has to do with the working of our own bodies ! 
We gaze with wonder and admiration at the marvellous 
work of some intricate machine made by man. Well 
we may, for it seems endowed with life. But, in the 
human body, we find, the more we study and think 
about it, not simply a most perfect and delicate machine, 
but one endowed with life, — a mind, — a soul. 



4 YOUNG FOLKS PHYSIOLOGY 

Indeed, the more we study, and the longer we live, 
and reflect upon it, the more we shall realize the great 
fact that the All-wise Creator, in his goodness and wis- 
dom, has made for us bodies, which, in the words of 
the Psalmist, are "fearfully and wonderfully made." 

4. Anatomy, Physiology, and Hygiene. — Before we 
can tell how plants and animals live, we must know what 
animals and plants are. A watchmaker would be una- 
ble to describe the working of a watch or clock unless 
he first made himself acquainted with the various parts 
of which watches and clocks are made. So it is with 
the study of human beings. We must know the struc- 
ture of their bodies before we can understand the man- 
ner in which these bodies act and move, or, in one 
word, live. 

The science which tells us about the structure, form, 
and position of the different parts of the body, is 
called anatomy. 1 It tells us what they are, where they 
are, and how they look. 

The science which explains the uses or functions of 
the different parts of the body is called physiology, 
meaning "a story about nature." 

Now, after we have learned something about the 
structure and uses of different parts of the body, we 
should learn how to take care of these parts, and 
how to keep them in health. We do this by the study 
of hygiene, 2 or the science which tells us about health. 

1 The word " anatomy " comes from the Greek, meaning " a cutting through," 
or dissection ; that is, the act of cutting an animal in pieces for the purpose of 
study. 

2 The word " hygiene " is derived from the name of the Greek goddess 
Hygeia, who is said to have watched over the health of the people. 



INTRODUCTION 5 

Take the stomach for an illustration. If we learn what 
it is, where it is, how it looks, its shape, size, and general 
appearance, its coats, etc., this would be its anatomy. 

If we learn for what special purpose it is made, just 
what these different parts do, and how they do it, this 
would be its physiology. 

Finally, if we learn what might interfere with the 
proper working of each part, and how it is kept in 
good order, — what will injure its health, and what will 
do it good, — this would be its hygiene. 

5. Some Technical Words Explained. — A child 
soon learns by experience many things about such parts 
of his body as the eye, the ear, the nose, the hands and 
feet, the tongue, and so on. Now, you must already 
know that there are other distinct parts inside of our 
bodies, although we cannot see them. You have 
doubtless heard of some of these parts, such as the 
heart, the brain, the stomach, the liver, and the lungs. 
It is usual to speak of these as the organs of the body. 

An organ is a special part of the body which performs 
a special work. Thus the eye is the organ of sight, 
the nose of smell, the ear of hearing, the stomach of 
digestion, the lungs of breathing, and so on. 

A number of organs, similar in structure, of differ- 
ent size and shape, extending throughout the body, is 
called a system. Thus we speak of the nervous sys- 
tem, the arterial system, etc. 

Several organs, different in structure, but so arranged 
as to work together for some special end are called an 
apparatus. Thus the stomach and liver make up a part 
of the digestive apparatus. 



6 YOUNG FOLKS' PHYSIOLOGY 

The special work which an organ has to do is said to 
be the function or use of that organ : thus it is the 
function of the eye to see, and of the liver to secrete 
bile. 

We speak of the body as being an organized struc- 
ture because it consists of a number of organs, each 
performing some function necessary to the whole. 
One important fact must be borne in mind. Although 
each of these organs is placed in a distinct part of the 
body, and has its own special work to do, yet no one 
exists and works for itself alone. The special work 

which eachperforms is necessary 
for the general well-being of the 
body as a whole, and cannot be 
carried on by another organ. 

Some of the organs are more 
intimately connected with the 
life of the body than others. We 
often speak of them as the Tital 
fig. i. -Portion of a lining tis- Organs. If any one of these be 

sue showing its bundles and filaments , . . . 

of fibrous tissue, crossing in every diseased or injured, so that it 

direction. The rounded bodies cannot carry Qn its prop er WOrk, 
represent a few fat-cells. Highly J - 1 *■ 

magnified. the rest of the organs sooner 

or later suffer too, cease to perform their functions, 
and death ensues. 

The organs and other parts of the body are composed 
of a variety of substances or materials. These we 
shall call the tissues of the body. They may be com- 
pared to the timber, stone, bricks, mortar, iron, lead, 
glass, and other materials, which, properly arranged, 
make up a dwelling-house. The principal tissues 





INTRODUCTION 7 

which make up the body are bone, or osseous tissue ; 
muscle ', or muscular tissue ; cartilage y or gristle ; fat and 
nerve tissue. 

6. Minute Structure of the Body. — When we 
examine any part of the body with the microscope, we 
find it made up mainly of fibres, fluids, 
and cells. The original element out 
of which every other element of the 
body is formed is the cell. The fibres 
serve to give firmness to the tissues 
or organs and to bind the most minute 
parts of the body together. Fibres FlG . 2 ._ W ith biood-ceiis 
are properly whitish or yellowish in ra P id motion, as seen 

under the microscope. 

threads, slender as one can imagine. 

Some are elastic ; others are not, but very tough and 

strong. 

The cells are so small that we must use a powerful 
microscope to see them at all. In a general way we 
may compare them to the tiniest bags filled with a 
semi-fluid mass, in which another still smaller bag 
floats, and is called the nucleus of the larger one. 
Cells are of all shapes and sizes, round, flat, thick, and 
long. Thus, we shall learn in a succeeding chapter of 
the rounded cells, or corpuscles, which float in the 
blood, and of the flattened cells which can be scraped 
from the outer or scarf skin. 

The life of a cell is one of ceaseless change. It is 
ever changing its form. If we watch the cells under a 
microscope, we find them dividing themselves into parts 
with the greatest rapidity. In their never-ending 
changes, they are doing a remarkable work in our bodies. 




8 YOUNG FOLKS' PHYSIOLOGY 

Some change their forms, and become muscle : others 
become fluids, which help digest our food. The liver- 
cells manufacture or secrete 
the bile, and the bone-cells 
help make the bones. Mil- 
fig. 3. — showing how a ceil divides lions of blood-cells do their 

into two new cells, each with its nucleus, as k d ^ , 

seen under the microscope. r J j > 

.while the brain-cells act in 
some mysterious way to help us think. In short, our 
very life exists in the cell. 

7. Chemical Elements found in the Body. — If 
we put aside the microscope, and call upon the chem- 
ist to help us, he will tell us that there are about sev- 
enty different elements known to chemistry. Of these, 
only sixteen exist in our bodies. The most important 
are carbon, hydrogen, nitrogen, oxygen, sulphur, iron, 
phosphorus, soda, potash, lime, and magnesium. Thus, 
there is iron in the blood, lime in the bones, soda in 
the bile, and potash in the muscles. 

Very few of these elements exist as such in the 
body. They are mainly found as chemical compounds. 
Thus, water, a combination of oxygen and hydrogen, 
forms about two-thirds of the weight of the body ; and i 
the average human body contains about six ounces of I 
common salt, which is a form of soda. 

8. General Build of the Body. — If we look at the | 
human body, we cannot help noticing that it is made | 
up of a middle, nearly round portion, which is called 
the trunk. On the top of this is placed a kind of round 
ball, called the head; while two pairs of branches, 
called the extremities, are attached to the upper and 
lower corners of the trunk. 



INTRODUCTION 



9 



Again, we notice that the whole body has an outer 
covering, which is called the skin. Underneath the 
skin lie soft masses of red flesh, called the muscles. 
These muscles are mostly fastened to the hard parts, 
or bones. These bones make up the framework of our 
bodies. There are about two 
hundred separate bones in the 
body, which they serve to sup- 
port. Taken together, they form 
the skeleton. 

The limbs are solid ; but the 
head holds an important organ 
called the brain, which is the 
centre of the nervous system. 
A delicate, silvery-white cord, 
called the spinal cord, runs from 
the brain down the middle of the 
backbone, and sends its thread- 
like branches, called nerves, all 
over the body. It is through 
the nervous system that we are 
able to think or feel, or, in fact, 
to know anything. 

The trunk is divided into an 
upper and a lower room by 
means of a movable partition 
called the diaphragm. 

The upper room is called the chest, and holds the 
heart and the lungs. 

The lower room is called the abdomen, and holds the 
stomach, liver, intestines, and other vital organs. 




Fig. 4. — Side view, showing the 

Diaphragm separating the 

Chest and Abdomen. 



IO 



YOUNG FOLKS PHYSIOLOGY 



9. General Plan of Study. — We shall now proceed 
to study some of the most simple facts about the human 
body, together with the laws of Hygiene that must be 
obeyed to insure its health. 




iiG. 5. — Contents of the Chest and Abdomen. 

Special emphasis will be laid upon the nature and the 
effects of alcoholic drinks, tobacco, and other narcotics. 

Reference will be made to the value and importance 
of physical culture. 

For convenience the whole subject will be considered 
under the following general topics : — 



INTRODUCTION 1 1 

GENERAL TOPICS. 

1. The Skeleton, or bony framework. 

2. Muscles, or the fleshy parts. 

3. Physical Exercise in Schools. 

4. Food and Drink. 

5. Origin and Nature of Fermented Drinks. 

6. The Digestion of Food. 

7. The Blood and its Circulation. 

8. The Respiration, or Breathing. 

9. The Skin, or Outer Covering. 

10. The Nervous System and the Brain. 

11. The Special Senses. 

12. Excretion, or getting rid of waste matter. 

13. The Throat and the Voice. 

1. The skeleton, or bony framework, consists of about 
two hundred bones of various shapes and sizes. It 
forms the main support of our bodies, ar.d serves to 
protect the vital organs within. 

2. The muscles are the fleshy or lean parts of the 
body ; and they, together with the fat, give to the body 
its general form and proportion. 

3. Physical exercise in Schools. Its practical impor- 
tance and value in promoting the health of young 
people. 

4. Food and drink are the materials necessary to keep 
up the warmth and growth of the body, and enable it 
to make its movements. 

5. Origin and Nature of Fermented Drinks. Alcoholic 
liquors described, and their injurious effects upon the 
bodily life fully discussed. 



12 YOUNG FOLKS' PHYSIOLOGY 

6. Digestion is the process of changing the food into 
a condition suitable for absorption into the blood. 

7. The blood is the vital fluid of the body. The 
course of the blood through the body is called its cir- 
culation. 

8. Respiration is the act of breathing. It is carried 
on mainly by the lungs. 

9. The skin, or the outer covering of the body. 

10. The nervous system enables us to move, see, feel, 
taste, and so on. The brain and the spinal cord are its 
central organs. 

11. The special senses enable us to touch, taste, smell, 
hear, and see. We often speak of them as the five 
senses, or the five gateways of knowledge. 

12. Excretion is the process by which the body gets 
rid of its waste matters, mainly through the lungs, skin, 
and kidneys. 

13. The throat and voice described. 



THE BONY FRAMEWORK 1 3 



CHAPTER II 

THE BONY FRAMEWORK 

10. The Skeleton. — Most animals must have some 
kind of a framework or support to give the body form 
or shape. This framework in many animals is a sup- 
port made up of a number of firm and hard substances 
called bones. 

The bones may be on the outside, like a coat of mail, 
as seen in the lobster and turtle; or there may be a 
framework of those inside of the body, moved by mus- 
cles outside, as seen in the codfish and shad. In fact, 
all animals that belong to the great backbone family 
have an inside framework. 

This bony support is called the skeleton, meaning a 
"dried up body." It is to the body what the ribs are 
to a vessel, or what the frame is to a house. Every 
one is familiar with the picture of the human skeleton. 
It shows us how the dead bones of the human body 
look when taken out, cleaned, and held by wires in 
their proper places. The human skeleton is made up 
of about two hundred separate bones, 1 of various sizes 
and shapes. 

1 To be more exact, 28 bones are counted in the head, including the three 
bones in each ear, 54 in the trunk, and 124 in the limbs. This number depends 
upon the time and how the bones are counted. 

The 32 teeth are not usually reckoned as bones. Several bones, which in youth 
are made up of separate pieces, unite in old age, and make one bone. The breast- 
bone, for instance, in the child, consists of eight pieces ; but in adult life it is 
made up of only three. 



H 



YOUNG FOLKS' PHYSIOLOGY 



The bones of the body thus arranged give firmness, 
strength, and protection to the soft tissues and vital 
organs, and form, as it were, the foundation upon which 
our bodies are securely built. 

ii. How Bone is made up. — Bone is a hard and 
strong substance, made up of animal matter united with 
certain mineral earths, as lime and potash. The earthy 
part of bone makes up about two-thirds of its weight, 
and the animal portion the other third. 

Put a slender chicken bone in a mixture of two ounces 
of muriatic acid and one pint of water, and let it soak 
for two or three days, and the earthy 
part will be dissolved, leaving only the 
animal matter. The form of the bone 
is kept ; but it can be easily bent, cut, 
torn, or even tied into a knot. 

Again, put a soup-bone into a hot 
fire, and let it burn for two or three 
hours. Take it out carefully, and, while 
the shape is still kept, the bone is brittle, 
and will readily crumble when pinched 
between the fingers. The animal part 
has been burned out, and only the white 
bone-earth is left. 

The lime gives hardness and firmness 
to the bones ; while the animal substance 
makes them elastic, tough, and flexible. 
The proportion varies with age. In 
childhood the bones have more animal 
matter than earthy: hence a child's 
bones do not break easilv, and, when broken, soon 




Fig. 6. — The outer 
bone of the leg, tied 
into a knot, after the 
hard mineral matter 
has been dissolved out 
by acid. 



THE BONY FRAMEWORK 



15 



knit together. In old age, there is more lime in the 
bones than animal matter : hence they are brittle, and 
easily broken. They unite slowly, and sometimes not 
at all. 

12. General Structure of the Bones. — If we take a 
long bone, like that from a sheep's leg, or even a part 
of a beef shin-bone, and saw it lengthwise, we see that 




Fig. 7. — A thin slice of bone, cut crosswise, as seen under the microscope. 



the ends are soft and spongy, while the shaft is hard 
and compact. It is hollow, and the central cavity runs 
almost the whole length of the bone. It is filled, in 
life, with a soft substance called marrow. 

If the bones were solid, they would be much too 
heavy for ordinary use. A bone may be hard as a rock 
on the outside, on account of its thin, dense layer of 
compact bony tissue, and yet be light because of its 
cavity and the trellis-work of loose, spongy texture at 
the ends. 



1 6 YOUNG FOLKS' PHYSIOLOGY 

Bones are of many different shapes, according to the 
uses to which they are put. Some are long, with hollow 
shafts, as the bones of the arm and leg; others are 
short, to give strength, as the bones of the fingers and 
toes ; some are flat, for protection, and to cover cavities, 
like the bones of the skull and shoulder-blades ; while 
others are of various odd shapes, and hence called 
irregular, as the bones of the backbone and ankle. 

13. Minute Structure of Bones. — When bones are 
alive or fresh, they have a pinkish-white color, caused 
by the blood which flows through every part of them. 
Take a long, slender bone, like a rib or a sheep's leg, 
and we find that it is elastic, and will bend. 

Now, if we scrape down on the bone with a sharp 
knife, we find that it is wrapped round with a tough 
but very thin covering, called the periosteum, meaning 

Power of Bone to resist Decay. — " The power of bone to resist 
decay is remarkable. Fossil bones deposited in the ground long before 
the appearance of man upon the earth have been found to exhibit a con- 
siderable portion of cartilage. The jaw of the Cambridge Mastodon 
contained over forty per cent of animal matter — enough to make a good 
glue — and others about the same. From this we see that a nutritious 
soup might be made from the bones of animals that lived before the 
creation of man. The teeth resemble bone in their structure, but resist 
decay longer ; they are brought up by deep-sea dredging, when all other 
parts of the animal have wasted away. The bones differ at different 
ages, and under different social conditions. In the disease called 
' rickets,' quite common among the ill-fed children of the poor in Europe, 
but somewhat rare in America, there is an inadequate deposit of the 
mineral substance, rendering the bones so flexible that they may be bent 
almost like wax. Exercise is as necessary to the strength of bone as to 
the strength of muscle ; if a limb be disused, from paralysis or long sick- 
ness, the bones lose in weight and strength as well as the soft parts. 
Bone is said to be twice as strong as oak, and, to crush a cubic inch of 
it, a pressure equal to 5,000 pounds is requisite." 



THE BONY FRAMEWORK 



17 



"about a bone." All bones are covered with perios- 
teum except where they go to form a joint. They would 
die if this covering were for any cause removed. 

Bones have a great number of blood-vessels, which, 
becoming very small and hair-like, pass through tiny 
holes, or tubes, in the bones, and bring materials for 
their nourishment and growth. The tiny tubes called 
"canals," through which the blood- 
vessels of the bones travel, can be 
seen only with a microscope. 
Round these tubes the bony matter 
is arranged in layers, and between 
these layers are small cavities. 
These cavities are joined to each 
other, and to the canal which they 
surround, by other extremely fine 
tubes. 

As seen under the microscope, 
the appearance is not unlike a small 
animal with a great many legs. 
Thus the bones are tunnelled, like honey-comb, with 
passages through which the blood — " the river of life " 
— flows in every direction. (Fig. 7.) 




Fig. 8. — Cross Section of Bone, 
highly magnified; the Canals 
are left white. 



THE HEAD. 

14. The Head. — The skeleton, or bony framework of 
the "house we live in," consists of the bones of the 
head, the trunk, and the extremities. 

The bones of the head include those of the cranium 
and those of the face. Together they form the strong 
box of bone commonly called the skull. 



18 



YOUNG FOLKS' PHYSIOLOGY 



cEBVic&v vnnEBir-fc- 



LAYIflVW 



JBOHBA* 

VEBTESE^ 




THE BONY FRAMEWORK 19 

The general shape of the head is that of an arch. 
The arch is the strongest shape in which the skull 
could be made, just as the arched bridge is the strong- 
est-shaped bridge which can be made to bear the heavy 
loads that have to pass over it. 

15. The Cranium. — The Cranium, or brain-case, is a 
kind of oval, bony shell, which holds and protects the 




Fig. 



■The Skul 



brain. It is made up of eight bones closely locked 
together by seams or sutures, somewhat like the dove- 
tailing used by carpenters. Let us arrange and de- 
scribe these eight bones thus : — 



One Frontal (forehead). 
Two Parietal (side of head). 
Two Temporal (temples). 



One Occipital (back of head). 
One Sphenoid (wedge-shaped). 
One Ethmoid (sieve-like). 



20 YOUNG FOLKS PHYSIOLOGY 

The frontal bone forms the forehead. It is this bone 
which gives a beauty of form and a dignity of person 
seen in no other animal in creation. 

Two bones make the sides, or walls, of the head. 
They are called the parietal bones, from a Latin word 
meaning a wall. They join the two temporal bones, 
which lie round each ear, and form the " temples." 

The occipital bone forms the lower and back part of 
the skull. This broad, flat bone rests on the topmost 
bone of the backbone, and is pierced by a large hole 
through which a long cord of whitish marrow, called 
the spinal cord, passes from the brain-case into the 
spinal canal, and runs down the whole length of the 
backbone. 

The sphenoid, or wedge bone, is wedged in between 
the bones of the cranium and those of the face, and 
serves to lock together fourteen of these bones. 

The ethmoid, or sieve-like bone, so called because it is 
full of holes, like a sieve, lies between the eye-cavities 
just at the root of tfte nose. The nerves of smell pass 
through the holes in this bone into the cavities of the 
nose. 

1 6. The Face. — All the bones of the face, except the 
lower jaw-bone, are firmly fixed to each other, and to 
the bones of the cranium. By their union, these bones 
form five cavities ; namely, the two large cup-like cavities 
called the orbits, the two nostrils, and the mouth. The 
orbits are hollow, bony sockets in which the eyes are 
placed. In the back part of each cavity is a crevice 
through which the nerve of sight (optic nerve) passes 
from the brain to the eye. 



THE BONY FRAMEWORK 21 

The face contains fourteen bones ; viz., — 

Two Malar (or cheek) bones. Two Palate bones. 

Two Nasal (or nose) bones. Two Lachrymal bones. 

Two upper Jaw-bones (upper One Vomer (ploughshare) bone. 

maxillary). Two Turbinated (spongy) bones. 

One Lower Jaw-bone (lower max- 
illary). 

Under the orbits, and overlapping the jaw-bones, we 
find the two malar, or cheek bones, which in some races, 
as the American Indians, are very prominent. The 
two bones that form the upper part, or bridge, of the 
nose, are called nasal bones. The lower part of the 
nose is gristle, and not bone. 

Next we, come to the two upper jaw-bones, containing, 
as we all know, some of our teeth. The rest of the 
teeth are fixed in the lower jaw-bone, which moves by 
means of a hinge-joint, so as to allow the opening and 
shutting of the mouth. 

The remaining bones of the face are small. Two 
bones, forming the back part of the roof of the mouth, 
are called the palate bones. Two little bones, partly 
forming the inside walls of the eye-cavities, are called the 
lachrymal bones, from a Latin word meaning a tear. 
There is, through each of them, a canal which carries 
the tears from the eyes to the nose. 

The vomer, or ploughshare bone (so called from its 
resemblance to the share of the farmer's plough), is situ- 
ated between the nostrils. Two delicate little bones 
within the nose-cavity, shaped like a scroll or horn, are 
called turbinated bones, from a Latin word meaning a 
whirl. 



22 YOUNG FOLKS' PHYSIOLOGY 

17. How the Bones of the Head are joined to- 
gether. — The bones of the head are joined together in 
a peculiar way. The edges of the bones of the cranium 
and face are shaped somewhat like the teeth of a saw. 

In adults, these edges fit into each other, and grow 
together, resembling the dovetailed joints in a cabinet- 
maker's vork : hence they are called sictures, from a 
Latin word which means a sewing or a seam. 

In infancy all of the bones of the skull do not meet, 
and the throbbing of the brain at the top of the head is 
easily seen. These openings are called fontanelles, 
"little fountains." The bones of the skull are not 
wholly welded together till the child reaches adult life. 
When the bones are knitted together, these sutures add 
greatly to the strength and resistance of the brain-case. 

THE TRUNK. 

18. The Trunk.— The trunk is that part of the body 
which supports the head, and to which the arms and 
legs are attached. It has two important rooms, or 
cavities. 

The upper one, called the thorax, or chest, consists of 
a bony framework formed by the breast-bone, ribs, and 
backbone. It contains the lungs, with which we 
breathe ; and the heart, which pumps the blood through 
the body. 

The lower part, or abdomen, holds the stomach, liver, 
bowels, kidneys, and other important organs. 

Between the chest and abdomen is stretched a broad 
muscle, which moves up and down as we breathe. 



THE BONY FRAMEWORK 23 

This is called the "midriff" by the butchers, or dia- 
phragm, from a word meaning a fence or a partition. 

The principal bones of the trunk consist of those of 
the spine, the ribs, and the hips. 

There are fifty-four bones in the trunk, and they are 
thus arranged : — 

( 7 Cervical (or neck) Vertebras. 
I. The Spine contains 26 sepa- | 12 Dorsal (or back) Vertebras. 

rate bones ^ 5 Lumbar (loins) Vertebrae. 

I Sacrum, or sacred bone. 



I: 



/ Coccyx, or cuckoo-bone. 
7 True Ribs. 
II. The Ribs, 24 bones . I 3 False Ribs. 



III. I Sternum, or breast-bone. 

IV. The 2 Hip-bones. 

V. The Hyoid bone. 



2 Floating Ribs. 



19. The Spine. — The spine, or backbone, serves as a 
support for the whole body. It is made up of a number 
of separate bones called vertebra, between which are 
placed pads, or cushions, of gristle. 

These cushions are elastic 1 or springy, yet thick and 
strong. They serve to break the force of any shock or 
injury which the spine may receive, just as the springs 
of a carriage lessen the jolting which would be felt 
without them. These soft pads also prevent any grat- 
ing or friction of one bone on another. They are also 
yielding; that is, are readily pressed together, else the 
backbone could not bend. 2 

1 The elasticity of these plates of cartilage is so great, that we are actually about 
half an inch shorter when we go to bed than we were when we got up in the morn- 
ing, by reason of their flattening out under the weight of the erect position. 

2 These bones, again, are prevented from yielding too much by strong tough 
straps, or ligaments, which stretch between them. If the separate bones were 
allowed too much freedom of movement, the spinal cord inside the canal would be 
crushed or twisted, and paralysis or death would at once follow. 



24 



YOUNG FOLKS PHYSIOLOGY 



The spine is really a pile of twenty-four separate 
bones, resting on and above a strong, 
three-sided bone called the sacrum, 
or sacred bone, which is wedged in 
between the hip-bones. The sacrum, 
although reckoned as one bone, 
actually consists of five distinct ver- 
tebrae, which grow together, however, 
and form a single bone in adult age. 

Joined to the lower end of the 
sacrum is a little, tapering bone called 
the coccyx, so named from its resem- 
blance to the beak of a cuckoo. 

The whole spine forms a pillar, or 
column, of bones, tapering as it goes 
up. At the top are seven cervical or 
neck vertebrae : below them are the 
twelve dorsal or back vertebrae, from 
which spring the ribs. The five low- 
est bones, called the lumbar, or loin 
vertebrae, are the thickest and largest. 

Each vertebra of the backbone is 
pierced with a hole through its centre ; 
and the separate bones are so placed 
one above the other, that these holes 
form a continuous tube, or canal, down 
which passes the spinal cord. 1 



Fig. 



-The Backbone. 



1 Imagine a number of spools placed one on another. The central hole through 
each would be exactly over the other, and there would be one long tube, or channel, 
through the whole string of spools. This is somewhat like the arrangement of 
the vertebrae of the backbone. 



THE BONY FRAMEWORK 



25 



In this bony canal the spinal marrow lies protected 
from injury. From each vertebra project spines, or 
thorns, of bones, to which are fastened muscles, which 
keep the flexible backbone erect, and lift the head and 
shoulders. The row of spines along the whole length of 
the backbone forms a ridge, which we can feel by press- 
ing with the fingers up and down the middle of the back. 

The spine is one of the most curious and wonderful 
things in nature, — so firm, and yet so elastic ; so stiff 
that it will bear a heavy weight, and yet bending like 
rubber ; a tapering pile of odd-shaped bones, so admira- 
bly planned, and so wonderfully put together, that the 
delicate brain resting upon it, and the spinal cord hidden 
within its bony canal, are 
not often hurt. The 
most daring athlete rarely 
breaks the bones of his 
spine, or puts them out of 
place. 

20. The Ribs. — The 
ribs are the slender, but 
strong, bony hoops which 
help make the framework 
of the chest. They pass 
around the chest, and 
strengthen it, resembling 
somewhat the hoops of a 
barrel. There are twenty- 
four ribs, — twelve on each 
side. The ribs are joined to the backbone behind, and 
in front to a flat, narrow bone, shaped somewhat like 




Fig. 12. — The Ribs and Sternum. 



26 YOUNG FOLKS PHYSIOLOGY 

an ancient sword or dagger, called the sternum, or breast- 
bone. This bone does not go down far enough to allow 
of all the ribs being joined directly to it. Only the four- 
teen upper ribs — that is, seven on each side — are thus 
fastened : they are on this account called the true ribs. 

The next six ribs, three on each side, come partly 
round from the spine, and then each is joined by gristle 
to the one above it. They are called the false ribs. The 
remaining four ribs, two on each side, spring from the 
spine, like their neighbors, but are not fastened to any- 
thing in front, and for this reason are called the floating 
ribs. 

The spaces between the ribs are filled with strong 
muscles, one set of which raises the ribs, the other 
lowers them. This barrel-shaped framework of bones 
that makes the chest, although strong, is not rigid. It 
can be raised and lowered, owing to the joints at the 
back, the cartilages, or gristle, in front, and the muscles 
between. The space within thus becomes larger, and 
more room is allowed for the action of the heart and 
lungs. 

How the Skull and the Spine are joined together. — The skull 

and the spine are joined in a peculiar manner. The first, or topmost, of 
the neck vertebrae is called the atlas, so called from the fabled Atlas of the 
ancients. In olden times, people believed that the earth was supported 
on the shoulders of a huge giant called Atlas. As, therefore, the head is 
supported by this bone, it received the name of atlas, after the fabled 
giant of old. 

On the lower part of the skull are two smooth rockers, which fit into 
two little smooth grooves hollowed out in the atlas. We are thus able to 
rock the head to and fro. The second vertebra of the neck is called the 
axis, and has a peg, called the odontoid process, or tooth-like peg, which 
fits into a notch in the atlas. Thus, when we turn the head sideways, the 
atlas turns around the peg of the axis. 



THE BONY FRAMEWORK 2*J 

21. The Hips. — The lower part of the trunk is 
formed by two large, irregular bones, very firm and 
strong, called the hip or haunch bones. They join the 




sacrum behind, and each other in front. The two hip- 
bones, with the sacrum and coccyx, form a kind of bony 
basin called the pelvis, in which many important organs 
are held. Each hip-bone has a deep, cup-shaped cavity, 
or socket, into which the rounded head of the thigh-bone 
fits. 

The Hyoid Bone. — Under the lower jaw is a little horseshoe-shaped 
bone called the hyoid bone because it is shaped like the Greek letter v. 
The root of the tongue is fastened to its bend, and the larynx is hung 
from it as from a hook. The hyoid, like the knee-pan, is not connected 
with any other bone. 

THE UPPER LIMBS. 

22. The upper Limbs. — Man has two upper and 
two lower limbs. Each upper limb consists of three 
parts, the upper arm, the fore-arm, and the hand. Each 



28 



YOUNG FOLKS' PHYSIOLOGY 



lower limb also consists of three parts, —the thigh, the 
lower leg, and the foot. 

In speaking of the bones of the upper extremities, 
however, it is usual to include the two shoulder-blades 
and the two collar-bones. Each upper limb, therefore, 
contains the following bones : — 



{Scapula, or shoulder-blade. 
Clavicle, or collar-bone. 
Humerus. 

Fore-aim j Rgdiu ^ 

{8 Carpal (wrist) bones. 
5 Metacarpal bones. 
14 Phalanges, or finger-bones. 

Making thirty-two bones in all. 

23. The Upper Arm. — There are two bones in the 
shoulder, and they serve to fasten the arm to the 
trunk. These are the scapula, or shoulder-blade, and 
the clavicle, or collar-bone. The shoulder-blade is a 
large, flat, three-sided bone, which is placed on the 
upper and back part of the chest, 
outside of the ribs. On the outer 
side it has a saucer-like cavity into 
which the rounded head of the arm- 
bone fits. 

The collar-bone has a double curve 
like the Italic letter/. It lies across 
the shoulder, like a kind of rigid bar, 
over and above the first rib. It 
serves, like the keystone of an arch, 
to keep the shoulders apart, and to 
hold them firm when the upper limbs are used. Its 




Fl& 14. — Back of Right 
Shoulder-Blade. 



THE BONY FRAMEWORK 29 

inner end is tied to the breast-bone, and its outer to 
the shoulder-blade. 

The humerus is the long, hollow bone of the upper 
arm. It fits into the socket of the shoulder-blade, and 
goes to the elbow, where it is joined to the two bones 
of the fore-arm. 

24. The Fore-arm. — The fore-arm contains two 
long, hollow bones, the ulna and the^ radius. 

The ulna is the larger of these two bones, and is 
joined to the humerus by a hinge-joint at the elbow. It 
is prevented from moving too far back by a process, or 
projection, which makes the sharp point of the elbow. 

The radius is the long, slightly curved outer bone 
of the fore-arm. It is smaller than the ulna. Its upper 
end is fastened both to the ulna and the humerus. Its 
lower end is much larger than its upper, and carries the 
hand. The radius is tied to the ulna in such a manner 
that it can glide nearly round it. This gives us the 
power of twisting the fore-arm and the hand. 

25. The Hand. — The hand consists of three parts, 
the wrist, the palm, and the fingers, containing in all 
twenty-seven bones. 

There are eight carpal, or wrist bones, all of which 
are very closely packed in two rows, and bound together 
with cords. The wrist is thus as strong as if made 
of a single bone, while at the same time it is capable of 
the most delicate movements. 

The metacarpal bones are the five long bones which 
form the palm of the hand. They are attached to the 
carpal bones of the wrist, and to the bones of the 
fingers. 



30 



YOUNG FOLKS' PHYSIOLOGY 



The phalanges of the fingers are the fourteen small 
bones which are tied end to end, to form the fingers. 
Each finger has three bones, each thumb two. The 
bones of the fingers are arranged in three rows, as will 
be seen by closing the hand. 

The wrist-bones, metacarpal bones, and finger-bones 
are all held in place by strong but flexible ligaments. 
By this beautiful contrivance, the greatest strength and 




Fig. 15. —Bones of Right Hand. 

elasticity are given to the hand, which is thus fitted for 
all kinds of work, from grasping heavy hammers to 
handling the pen, and threading the finest needle. 

THE LOWER LIMBS. 

26. The Lower Limbs. — The general structure 
and number of the bones of the legs bear a striking 
similarity to those of the arms. Thus the leg, like the 
arm, consists of three parts, the thigh, the lower leg, 
and the foot. 



THE BONY FRAMEWORK 3 1 

There is only one bone in the thigh, while there are 
two in the lower leg. We see that this is a similar plan 
to that of the arm. In the foot, the tarsal or ankle bones 
correspond to the carpal bones of the wrist ; while the 
metatarsal bones and the phalanges of the foot take the 
place of the metacarpal bones and the phalanges of 
the hand. 

The bones of the leg are, — 

Thigh Femur, or thigh-bone. 

{Patella, or knee-pan. 
Tibia, or shin-bone. 
Fibula, or splint-bone. 
{7 Tarsal, or ankle-bones. 
5 Metatarsal, or instep-bones. 
14 Phalanges, or toe-bones. 

Making thirty bones in all. 

27. The Thigh The top bone of the leg is the 

femur, or thigh-bone. It is the largest and strongest 
bone of the body. It has a rounded head, which fits 
into a cup-like cavity in the hip-bone. At the knee- 
joint the thigh-bone meets the bones of the lower leg, 
to which it is fastened by strong cords. 

28. The Lower Leg. — The lower leg consists, like 
the fore-arm, of two bones. The larger, a strong, 
three-sided bone, with a sharp edge in front, is called 
the tibia, and is commonly known as the shin-bone. 

The smaller bone, bound at both ends to the tibia, is 
called the fibula, meaning a clasp. It is a long, slender 
bone on the outside of the leg, and its lower end forms 
the outer ankle. It is often spoken of as the small 
bone of the leg. 

Covering in part the knee-joint is a flat, three-sided 
bone, called the patella, or knee-pan, which protects the 
joint, and gives firmness to the leg. 



32 



YOUNG FOLKS' PHYSIOLOGY 



29. The Foot. — The foot, like the hand, consists of 
three parts, the bones of which are known as the tarsal 
bones, the metatarsal, and the phalanges of the foot. 

The tarsal, or ankle-bones, are seven in number, and 
form the heel, the ankle, and part of the sole of the 
foot. These seven irregular bones are tied firmly 
together by straps, or ligaments, and are strong enough 
to bear the weight of the body. The large bone, 



Xi PHALANGOS 
*OBM!NQ TOt'S 




7 TARSAL BONES 
FORMING ANKLE 



E METATARSAL 

BONES 



ASTRAGALUS 
HEEL-BONS 



Fig. 16. — Bones of Foot and Ankle. 

which projects backwards, is the heel-bone ; and on the 
bone over this the shin-bone rests. The heel-bone is 
connected with the great muscles of the calf of the 
leg by a very strong cord, or tendon, called the tendon 
of Achilles. 1 

1 The warlike deeds of this famous Greek hero were sung by Homer. Ac- 
cording to the story, Achilles received his death-wound in the heel, no other part 
of his body being vulnerable. 



THE BONY FRAMEWORK 33 

The metatarsal bones, like the palm of the hand, are 
five in number, and form the instep of the foot. They 
are the connecting link between the ankle-bones and 
the phalanges of the foot. 

The bones of the toes, or phalanges, number fourteen 
in all, three in each toe, with the exception of the 
great toe, which, like the thumb, has only two bones. 

30. Use of the Bones. — Bones serve many useful 
purposes. They keep up the general shape of the 
body. The skeleton, as we have seen, is its framework. 
It gives strength and support to the soft and fleshy 
parts. If there were no bones, and the whole body 
were a mass of flesh only, the legs would give way, and 
finally be crushed down, under the great weight of the 
body. 

Again, bones protect the soft organs which lie be- 
neath them. The bones of the head protect the soft 
and delicate brain in a complete box of bone : the ribs 

The Hand and Foot Compared. — The toes and fingers correspond 
exactly in their number and the character of their bones, the great toe 
holding the same place in the foot as the thumb does in the hand. In 
the hand the wrist-bones are small and the finger-bones long and slender. 
The thumb is made to move in the opposite direction to the fingers, and 
thus the hand becomes adapted for grasping purposes. Indeed, the hand 
may be either a most delicate pincer or a powerful vise, while its flexi- 
bility and rapidity of motion can nowhere be better seen than in the 
rapid movements of the skilful musician on the keyboard of the piano 
or organ. 

Now look at the bones of the foot. The ankle-bones have a clumsy 
look, and all the hollow bones are short, thick, and heavily jointed. It 
is at once clear that strength, and not flexibility, is the object of these 
bones. The feet, which are to support the entire weight of the body, 
are thus better adapted to do their work than they would be if built of 
slender, long bones like those of the hand. 



34 YOUNG FOLKS PHYSIOLOGY 

protect the heart and lungs in a large cage of bone, 
and so on. Passage-ways and little cavities are hol- 
lowed out of solid bone to lodge and shield important 
organs. Grooves and canals are formed in the hard 
bone to receive and protect tender organs, delicate 
nerves, and tiny blood-vessels. 

Finally, the surfaces of bones are fitted with grooves, 
knobs, and sharp edges, to which muscles are tied. 
We are thus enabled to stand erect, and make with ease 
and quickness the countless movements of the body. 
The blood filters through bone as freely as it does 
through any other living tissue. The bone-structure is 
ever changing. Old material is got rid of, and new 
matter takes its place. 

31. Repair of the Bones. — When a bone is broken, 
blood trickles out between the injured parts, and after- 
ward gives place to a sticky, watery fluid, which .grad- 
ually becomes thicker, like sirup or jelly. This slowly 
hardens into a new bone-structure, and forms a kind of 
cement to hold together the broken ends. Nature does 
not spare her healing cement. The excess bulges out 
around the place of union, over which a bunch is felt, 
for a lifetime perhaps, under the skin. 

In young people, a broken bone will knit together in 
two or three weeks ; while in grown-up people six 
a or more will be required. In aged persons, a 
broken bone may cripple them for life. It is then a 
tedious matter, and sometimes the bones will not unite 
at all. 

er a bone has been once broken, it is fragile for 
some time ; and great care should be taken lest it be 



THE BONY FRAMEWORK 



35 



broken a second time before it firmly unites. When a 
bone is broken, the ends tend "to ride" over each 
other, because the muscles pull the broken portions 
apart ; hence the need 
"to set" the bone by- 
drawing the injured bone 
into place, and keeping 
it so by splints and ban- 
dages, properly applied 
by a surgeon. 

32. How Bones are 
joined together. — The 
place where two bones 
join together is called a 
joint. 

Joints vary according 
to the kind and amount 
of motion. Get a knuckle 
of ham, mutton, or a 
beef-joint at the market. 
Cut into it, open up the 
joint, and study its 
structure. In all joints, 
the essential parts are 
the same. The ends of 
the bones are shaped 
according to the special FlG 
needs of each joint. 

The joint-end of the bones is smooth, moist, and 
tipped with a thin layer of gristle, or cartilage. This 
smooth and glistening covering is bathed by a sticky 




17. — The Right Knee-joint, showing how 
firmly it is bound about by ligaments. 



36 



YOUNG FOLKS PHYSIOLOGY 



fluid called the synovial fluid, so named because it is 
like the white of a raw egg. This is the oil often 
spoken of as "joint-oil," furnished by nature to allow 
the rubbing-surfaces to move smoothly over one another, 
and thus prevent too much wear and tear. 




Fig. iS. — Showing how the Wrist-Bones are tied together. 



There are two principal kinds of joints. the_/fov</and 
the movable. Thus, the bones of the head, as we have 
seen, are firmly dovetailed into each other by jagged, 
saw-like edges, which grow into each other from in- 



THE BONY FRAMEWORK 37 

fancy. The bones of the sacrum are also firmly united 
to each other. These are the " fixed" joints. 

Movable joints allow the bones to glide on each 
other with more or less freedom of motion. They 
differ according to the motion needed. Such a joint 
as that at the hip is called a " ball-and-socket joint," 
because the rounded head of the thigh-bone fits into 
the cup in the hip-bone. The ball-like head of the 
arm-bone works in the cavity of the shoulder-blade, 
and makes another ball-and-socket joint. Such joints 
allow a greater variety of motion than any other kind. 

Again, bones are grooved and ridged so that one 
bone can glide over the other to and fro, like a door on 
its hinges. This is called a "hinge-joint." Such joints 
are found at the knee, and between the lower jaw and 
cranium. The bones of the fingers also move on each 
other in this way. Sometimes a kind of peg in one 
bone fits into a notch in another, and forms a "pivot- 
joint." The two bones (atlas and axis) at the top of 
the spine are joined in this way. 

33. How Bones are tied to each other. Liga- 
ments. — The bones are tied together, kept in place, 
and their movements limited, by tough and strong 
bands, or straps, called ligaments, meaning "to bind." 
They may be seen in any of the movable joints, — say 
of the calf, sheep, or chicken, — and have the look of 
white, silvery cords. 

Some of the ligaments are as thin as a piece of paper ; 
while others, as at the side of the knee, or at the 
shoulder, are very thick. Some cross each other, as in 
the knee-joint; while others go all round the joint, and 



38 



YOUNG FOLKS PHYSIOLOGY 



completely shut it up in a bag. This prevents the 
bones from being easily dislocated, or slipped out of 
place. 

It is a difficult matter to carve a turkey or a fowl, 
because one has to cut through these ligaments before 
he can cut the limbs apart to serve it out in pieces. 

There is the same diffi- 
culty in separating the 
two bones in a shoulder 
or leg of mutton, be- 
cause they are held 
firmly together by 
strong ligaments. 

34. Hints about the 
Health of Bones. — The 
bones of children are 
flexible, and capable of 
being bent by long-con- 
tinued strain; because 
there is more animal 
matter than in later 
years. Therefore great 
care must be taken with 
the positions which 
children take at home, 

tic 19. — A School-girl sitting at her Desk in a 11 

position often resulting in Curvature of Spine. at SChOOl,and elsewhere. 

Allow a child to walk 
too early, before the legs are strong enough to bear the 
weight of the body, and " bow-legs " result. 

At school, the desks should not be too low, thus 
causing a forward stoop ; or too high, thereby throwing 




THE BONY FRAMEWORK 



39 



one shoulder up too much, and giving a twist to the 
spine. If the seats are too high, the feet have no sup- 
port, and injury to the thigh may result. If too low, 
there is undue strain on the shoulder and backbone. 
Round shoulders and curvature of the spine may result 
from long-continued positions of this kind. 

The feet should rest 
firmly on the floor, and 
the edge of the desk 
should be about one inch 
higher than the level of 
the elbows. A line 
dropped from the edge 
of the desk should strike 
the edge of the seat. 
Three sizes of desks 
should be used in every 
schoolroom, and more 
in ungraded schools. 
Seats should be regu- 
lated according to the 
size of the pupil, and 
frequent changes of 
seats should be made. 

Young people shoukL 

° x L Fig. 20. — A correct Position at the School-desk, 

not get into the habit with no undue Strain on the Spine. 

of taking hurtful posi- 
tions, such as sliding down into the seat, sitting on the 
foot, or on the small of the back. Bending over too much 
while reading, writing, sewing, or otherwise at work, 
is apt to cause spinal curvature and round shoulders. 




40 YOUNG FOLKS PHYSIOLOGY 

The prevailing fashion of using tight and high-heeled 
boots and shoes cannot be too strongly condemned as 
both hurtful and ugly. High heels throw the weight of 
the body forwards, and force the foot down on to the 
toes. This will in time not only crowd all shape out of 
the toes, causing tender feet, corns, bunions, distorted 
joints, and in-growing nails, but makes the natural gait 
stiff and ungainly. 

35. Effect of Alcohol and Tobacco on the Bones. — 
Since the bones constitute the framework of the body, 
a person's form depends upon the size and shape of his 
bones. The bones grow during childhood and youth ; 
whatever growth one loses during that time cannot be 
afterward made up. It is the testimony of sagacious 
physicians that alcoholic drinks and tobacco tend to 
check the growth of the bones. 

The smoking of cigarettes is especially hurtful to 
growing boys, because such a habit tends, besides other 
harmful things, to dwarf the growth of the bones. A 
well-developed form is something to be prized. No 
wise boy or girl will risk attaining it by indulging in 
filthy or injurious habits while young. 

See Note 1, page 355. 



THE BONY FRAMEWORK 



41 





I. Cranium (8 bones) . 


f 1 Frontal (forehead), 
1 2 Parietal (side of head), 
! 2 Temporal (temples), 
'1 1 Occipital (back of head), 
1 1 Sphenoid (wedge-shaped), 
I 1 Ethmoid (sieve-like). 


< 2 
W £ 

00 

W 
H 


• 
1 

! II. Face (14 bones) 


f 2 Malar (cheek), 

2 Nasal (nose), 
1 2 Upper Jaw-bones, 
! 1 Lower Jaw-bone, 
' "J 2 Palate bones, 

2 Lachrymal bones. 

1 Vomer (plough-share) bone, 
I 2 Turbinated (spongy) bones. 




III. The Ear (6 bones) .• . 


( Hammer, 

Anvil, 
( St'urup, 




I. Spinal Column (26 bones) 


( 7 Cervical (neck) Vertebrae, 
1 12 Dorsal (back) Vertebra?, 
• -{ 5 Lumbar (loins) Vertebras, 
1 Sacrum (sacred bone) 
1 Coccyx (cuckoo-bone) 


I 2 If 

Pi £ 


II. The Ribs (24 bones) . 


( 7 True Ribs, 
• \ 3 False Ribs, 
( 2 Floating Ribs. 




III. Sternum (breast-bone). 

IV. Two Hip-bones. 
V. Hyoid Bone. 




CO 

pq 


Upper Arm ? 


( Scapula (shoulder-blade), 
• ] Clavicle (collar-bone), 
( Humerus (arm-bone). 


2 | 
j 

Ph 
Ph 
P 


Fore-arm .... 


( Ulna (fore-arm), 

1 Radius (spoke-bone). 


Hand .... 


( 8 Carpal (wrist) bones, 
• J 5 Metacarpal (palm) bones, 
( 14 Phalanges (fingers). 


CO 


Thigh .... 


Femur (thigh-bone). 


2 | 

< 

W vg 


Lower Leg 


( Pateila (knee-pan), 
• ) Tibia (shin-bone), 
' Fibula (splint-bone). 





Foot . . . * . 


( 7 Tarsal (ankle) bones, 
• J 5 Metatarsal (instep) bones, 
( 14 Phalanges (toes). 



42 



THE MUSCLES 



CHAPTER III 



THE MUSCLES 



36. The Muscles. — The smallest child or the tiniest 
insect can move its own limbs when it pleases, but the 
largest vegetable and the sturdiest tree never move 
•except some cause outside of themselves acts upon 
them. 

Movement in man is made by muscles. The limbs 
are moved by muscles. Even the motions of the 
stomach and the action of the heart are controlled by 
muscles. Muscles move the skin. In many animals 
this action is well marked, as when the horse shakes 
his hide to get rid of biting flies. Muscles move the 
bones, the fingers, and toes, the mouth, and the eyelids. 
In brief, all motion in the body is dependent upon 
them. 

37. The Structure of Muscle. — Muscle is simply the 

lean meat, or flesh, of the 
body. When we eat beef- 
steak or lean mutton for 
dinner, we are eating mus- 
cle. 

Muscles are made up of 
bundles of fleshy strings 
called fibres held together 
by a very thin web of tis- 
sue, not unlike the thinnest of tissue paper. Each fibre 




Fig. 21. — A Muscular Bundle teased out 
to show its Fibres. 



THE MUSCLES 



43 




Fig. 22. — A Fibre of Muscle, showing the 
separate Disks of which it is composed 
at a and b. 



is made up of a great many smaller fibres, called fibrils, 
held together in the same way. Each fibril consists of 
rows of little cells, arranged like a string of beads. 
This gives the muscles 
a peculiar striped look un- 
der the microscope, which 
marks the ordinary mus- 
cles of the body. 

When corned beef has 
been " boiled to rags," as we say, the web of connecting 
tissue is partly dissolved by heat, and the fibres are 
plainly seen. 

38. How Muscles act. — Muscles have a peculiar 
power of their own. This is the power to contract, or to 
shorten themselves. 

In order for a muscle to 
act, it must be stimulated. 
This stimulus, or that 
which gives it the power 
to act, is the nerve-force 
flowing through the nerves 
distributed to the muscles. 

Contraction is not, how- 
ever, the natural state of 
a muscle. After a longer 
or shorter time, it is tired, 
and begins to relax. Even the heart, the hardest- 
working muscle of the body, pumping blood night and 
day all the days of our life, has a short time to rest 
between its beats. 




Fig. 23. 



Portions of the Muscular Fibre 
highly magnified. 



44 



YOUNG FOLKS PHYSIOLOGY 




FlG- 24. — Principal Muscles of the Front of the Body. 



THE MUSCLES 45 

39. Kinds of Muscles. — Muscles are of two kinds, 
voluntary and involuntary. 

Voluntary muscles are those which can be made to 
act under the influence of the will. Such muscles make 
up the bulk of the fleshy parts of the body, and form a 
covering for the bony skeleton. 

The involuntary muscles are those which carry on 
their work without the use of the will — indeed, we can- 
not prevent them acting. Among these muscles may 
be mentioned those of the stomach, the bowels, the 
lungs, and the heart. When they contract, they force 
along the contents of these organs. In this way the 
blood is forced out of the heart, the food out of the 
stomach, and so on. If these muscles were not entirely 
independent of the will, they would cease to act the 
moment we fell asleep, and death would be the result. 
Hence these muscles continue to work at all times, 
because the will has no power over them. 

40. Arrangement of Muscles. — The muscles are 
arranged, for the most part, so as to oppose each other 
in action. Thus, when one set produces motion in one 
direction, there is, opposite to it, another group of mus- 
cles, which draws the part moved back into place again. 

When a piece of lean meat is brought from the 
market, it looks like a solid mass of flesh. It really con- 
sists of parts of several distinct muscles. Each of these 
muscles, when separated, will have the following form : — 

A middle or thick part. Two tapering ends, one 
attached to a fixed bone, and called the origin; the 
other connected with a movable bone, and called 
the insertion of the muscle. These tapering ends 



46 YOUNG FOLKS' PHYSIOLOGY 

are attached, or tied, to the bones by means of sinews, 
or tendons. 

As a muscle acts only by contracting, each movable 
bone must be supplied with at least two opposing mus- 
cles. One of these contracts, and draws up the limb : 
this is called a flexor muscle. The other, on the oppo- 
site side, by contracting, stretches out the limb : this is 
called an extensor muscle. 

Take, for instance, the two main muscles of the arm. 
When we bend the arm, we notice that the muscle in 
front of the upper arm swells up, and becomes hard. 
This is the biceps, or two-headed muscle, which has con- 
tracted in obedience to the will, and by its contraction 
has drawn up the fore-arm. When we wish to straighten 
the arm, we do not merely relax this muscle ; for, if we 




Fig. 25. — Biceps and Triceps Muscles. 

did, the arm would simply fall into the straight position. 
A muscle at the back of the upper arm, called the tri- 
ceps, the three-headed muscle, now contracts in obedi- 
ence to the will, and by its contraction straightens the 
muscle. 



THE MUSCLES 



47 



41. The Tendons. — If we bend the leg or arm, and 
grasp the inside bend of the joint with the hand, we feel 
the motion of cords just beneath the skin. These are 
the tendons, or sinews, forming the tapering ends of 
muscles, which are fastened to the bone, 

Tendons are white, glistening cords, like belts or 
straps, which connect the muscles with the bones. They 




Fig. 26. — Muscles and Tendons of the Hand. 

are very strong, but flexible. Children often amuse 
themselves by taking the leg of a fowl, a rabbit, or some 
small animal, and moving the toes by pulling a white 
cord in the leg. This cord is a tendon. Tendons are 
most numerous about the joints, especially the larger 
ones, like the knee and elbow. They save a great deal 
of space, and allow great freedom of movement, where 
muscles large enough to do the work would be exceed- 
ingly bulky and clumsy. 



4 8 



YOUNG FOLKS PHYSIOLOGY 



The longest and strongest tendon in the body is the 
tendon of Achilles. The tendons of the muscles which 
bend the knee, and are felt in the bend of the joint, are 
commonly called the " hamstrings." 




Fig. 27. — Muscles of the Face and Neck. 

42. The Bony Levers of the Body. — The word " lever " 
means simply a rigid bar, or rod, which moves about a 
certain fixed point, called the fulcrum. We have all 
seen a man trying to raise a heavy stone with a crowbar. 
He places one end of the bar under the stone, and 



THE MUSCLES 49 

presses down the other end. In this case, the bar is 
the lever, and the ground under the bar the fulcrum. 
The pressure which the man applies is called the power, 
and the stone to be lifted is called the weight. 

We have the same thing in a seesaw, where the plank 
is the lever, and the block on which it rests, the ful- 
crum ; while the power and weight are first at one end, 
and then at the other. In a lever, then, we have three 
things to consider, — the fulcrum, the power, and the 
weight. Levers are divided into different classes, 
according to the position of these three things. 

(i) First Class. — Levers of this class have the ful- 
crum in the middle. 

(2) Second Class. — In this class, the fulcrum is at 
one end, the power at the other, and the weight in the 
middle. 

(3) Third Class. - — In this class, the fulcrum is at one 
end, the weight at the other, and the power between 
them. 

In the various movements of the body, we have 
instances of all three kinds of levers. 

The skull, as it nods backwards and forwards upon 
the atlas, is an instance of the first class of levers. It 
is like the seesaw we have just spoken of. The skull 
rests on the spinal column, which is the fulcrum ; the 
muscle at the back of the neck is the power, and the 
front part of the skull is the weight. We have all seen 
a woman running a sewing-machine with her feet. In 
this case, the ankle-joint is the fulcrum ; the tendon of 
Achilles, attached to the heel-bone, is the power ; and 
the weight is at the toes. 



50 



YOUNG FOLKS PHYSIOLOGY 



Fig. 28. 



This is another instance of the 
first class of levers. When we 
stand on tiptoe, the power re- 
quired to raise the body is ap- 
plied to the heel-bone by its stout 
tendon. The toes are the ful- 
crum, and the bones of the foot 
support the weight. We have in 
this case a lever of the second 
class. 

The third class of levers is the 
one which occurs most frequent- 
ly in the body. Of this we have 
an example when we bend the 
fore-arm. The elbow is the ful- 
crum, the fore-arm and hand are 
the weight, and the biceps mus- 
cle, at its insertion in the radius, 
is the power which is thus placed 
between the weight and the ful- 
crum. 

43. A Few Important Muscles. 
— There are about five hundred 
muscles in the human body, all 
necessary for performing the va- 
rious movements and operations 
of this complicated machine, — 
our body. There are about fifty 
in each arm and hand. Six 
little muscles move each eye- 
ball. 



THE MUSCLES 



51 



Muscles are of all kinds of shapes, — round and flat, 
long and short, fan-shaped, etc., — suited to the work 
they are to do. Some are large, like the great breast- 
muscles ; while others are 
very small, like the tiny mus- 
cles which move the delicate 
little bones of the ear. Each 
muscle has its own name, 
given to it from its peculiar 
shape or size, or from the 
work it has to do. We chew 
our food by the help of two 
strong muscles, called the 
" chewing-muscles," which 
move the jaws. They are 
very large and strong in 
flesh-eating animals, like the 
lion and tiger. 

Turn the head suddenly to 
one side, and the sharp edge 
of a long muscle is plainly 
seen and felt on each side 
of the neck : one end is tied 
to the skull, the other to the 
collar-bone. It acts to turn 
and brace the head. Inside 
the cheek is a flat muscle, 
called the trumpeter's mus- 
cle. It is largely developed 
in glass-blowers, and persons 
who play on wind-instruments. 




Fig. 29. — Muscles of the Sole of the 
Foot, first layer. 

The muscle on each 



52 



YOUNG FOLKS' PHYSIOLOGY 



side of the chest is fan-shaped, and powerfully developed 
in strong men. 

The large, thick muscle covering the shoulder is 
thought to resemble the Greek letter 4 (delta). A 

military officer wears his 
epaulet over this muscle. 
The action of the two- 
headed muscle, which 
bends the fore-arm, and 
the three-headed, which 
straightens it, has been 
explained. A three- 
sided muscle covers the 
shoulder-blade, like a 
monk's hood, and helps 
move the shoulder. A 
very broad muscle in the 
back is the "climbing- 
muscle" of the body, 
and helps pull the arm 
backwards. 

Three huge muscles 
make up the greater por- 
tion of the fleshy mass 
in the lower part of the 
back. They move the 
thigh backwards, and help keep the body erect. The 
longest muscle in the body, called the " tailor's mus- 
cle," runs across the thigh in front. It helps us to 
cross the legs. Two strong muscles form the largest 
part of the calf of the leg. The tendons of these two 




Fig. 30. — Some large Muscles of the Back. 



THE MUSCLES 53 

muscles unite to form the tendon of Achilles. These 
muscles are used in walking, standing, dancing, and leap- 
ing. They are of great strength ; because in raising 
the heel, they have to raise the weight of the body. 

44. Effect of Alcohol on the Muscles. — We have 
learned that it is the nerve-force acting upon the muscles 
which makes them contract or relax. Now, if we drink 
more or less of alcoholic liquor, the muscles are acted 
upon in a peculiar way. The nerve-force that controls 
the muscles is weakened, and they show a lack of con- 
trol. 

The delicate movements which require the long train- 
ing of certain muscles, as in handling fine tools and 

Fatty Decay due to Alcohol. — All the important organs of the 
body have special work of some kind to do, and a peculiar power of 
doing it. They are made up of various forms of albuminoid matter 
endowed with living powers which vary with the different tissues. Thus, 
muscle is made up of fibres which have the power of contraction ; and 
nerves, of delicate threads which carry nerve impulses. 

Now, alcohol has the power of changing this vital property of the 
organs, someway related to albumen, into fatty or oil globules. This we 
may, for convenience, call fatty decay. Scientific men call it "fatty 
degeneration." It simply means that fat takes the place of the albumi- 
noid matter. In brief, there is a decay in the living body of parts of 
our most important organs. 

This decay occurs most frequently in the tissues of the heart and 
liver ; but it may go on in the blood-vessels, in the muscles, in the 
nerves, and, indeed, in all the vital organs. Alcohol taken for some time 
often causes this fatty decay. Other poisons, as phosphorus, produce it 
more rapidly; but alcohol causes it in a much more general way. The 
structure of the organs thus diseased is weakened, and their function 
seriously impaired. 

The heart, which is composed chiefly >of muscle, is very liable to 
become diseased through the unhealthy accumulation of fat caused by 
beer-drinking. 



54 



YOUNG FOLKS PHYSIOLOGY 



doing gymnastic feats, cannot be made. A person may 
know the right way of making each movement, and 
may succeed, after a fashion, in clumsily doing it ; but 
the trained muscles are no longer wholly under the 
control of the will. If alcohol enough is drunk, all mus- 
cular control may be lost, and deep breathing may be 
the only sign of life. 

This same lack of control is shown in the act of 
speech. Each and every word we utter requires special 
movements of the muscles of the tongue, palate, and 
throat, all acting in harmony. After drinking alcohol, 
there is less control of the muscles : the reins are 
slackened, so to speak ; words may be left out, cut short, 
or misplaced. According to the stage of intoxication, 
the words are clipped, stammered, or " mouthed," or 
"thick," from loss of control of the tongue. 

The muscles that move the eyes do not act in har- 
monv : hence the drunken man "sees double." The 
rapidity with which this loss of control is produced 
varies with the individual, with the kind of drink, the 
rate at which it is drunk, and many other circumstances. 

45. Effect of Alcohol on Muscular Strength. — 
People have supposed that alcohol gave them strength 
for their work, and rested them when they were tired. 
In both cases this supposition is wrong. Instead 
of adding to strength or diminishing weariness, it 
only deadens the nerves and impairs the judgment. 
For when the strength is tested with a health-lift 
or other means, the drinker is found to be weaker 
after taking an alcoholic liquor than before. After 
the effect of the alcohol has passed off, the feeling 



THE MUSCLES 55 

of weariness is more intense than before, show- 
ing that the alcohol did not remove it, only con- 
cealed it. 

A repetition of the drink may again create insensi- 
bility to the fatigued feeling, and the muscles may again 
obey the will ; but only for a briefer time than before. 
In this way the man who could have put forth just as 
much strength in an emergency, and could have held 
out longer, accomplishes less work, abuses his muscles, 
and deludes his mind by resorting to alcoholic drinks. 
He has also the injurious effects of the alcohol on other 
parts of his body to contend with afterward. 

Physiologists tell us that by the use of the micro- 
scope in the dissecting-room they find a notable differ- 
ence between the muscles of the heavy, inactive beer- 
drinker and those of the total abstainer. The latter 
are firm, elastic, and of a bright red color. The former 
are pale, flabby, and often loaded with fat. 1 Tiny par- 
ticles of fat collect in and around the muscle fibres, 
and crowd upon them, greatly reducing their strength. 

46. Effect of Tobacco on the Muscles. — Tobacco 
causes relaxation of the muscles, and weakens the 
nerves which control muscular movement. The result 
is seen in the unsteady hand of the cigarette-smoker 
when he attempts to draw a straight line or do other 
nice work which requires precision of touch. And his 
loose, shuffling gait gives observers the impression that 
his muscles are too weak to hold his bones together. 2 

1 See Note 2, page 356. 2 See Note 3, page 358. 



56 YOUNG folks' physiology 



CHAPTER IV 

PHYSICAL EXERCISE 

47. Why we need Physical Exercise. — To be vig- 
orous and healthy, every organ of the body must be 
used. Every organ and every tissue must act well its 
part to be of the best service. To keep the body in 
health, it is absolutely necessary that a certain amount 
of muscular action or physical exercise should be taken 
every day. 

The reason for this is plain : the body is made up of 
certain tissues, such as bone, muscles, and nerves. 
These tissues consist of a countless number of little 
cells, as we have learned, every one of which is born, 
lives its brief moment, then dies, and is cast out as 
waste or dead matter. The ever-changing blood, in its 
ceaseless current, brings them their nutriment. The 
tissues take what is specially suited to their wants, 
and return as waste matter whatever has become used 
up. 

Now, in every tissue, especially in the muscular 
tissue, this process is hastened by action. Exercise 
causes more frequent changes in the tissue-cells, and 
hence an increased flow of blood. The greater the 
amount of judicious exercise, the greater is the work- 
ing-power of the individual. Muscular activity is, then, 
the chief agent in bringing about these wholsome 
tissue-changes. 



PHYSICAL EXERCISE 57 

Muscles increase in size and strength according to 
the use made of them. The blacksmith uses' vigor- 
ously the muscles of his right arm day after day, hence 
their size and strength become well developed. Change 
his business for that of a clerk, and the once brawny 
arms soon become small and weak. Let a muscle be 
kept idle for some time, and it loses in bulk and vigor. 
Some of us have heard of certain people in India, who, 
as an act of worship, keep one arm raised above the 
head for many weeks. The muscles shrivel, and the 
arm dries up and becomes useless. If a leg is broken,' 
and kept in splints for several weeks, the muscles 
become feeble and wasted. It is only after a great 
deal of exercise, that the long-idle limb regains its 
former size and vigor. 

48. Effect of Exercise on Various Organs. — Not 
only are the muscles themselves benefited by exercise, 
but, by their action, many other tissues and organs 
become more vigorous. The heart beats more vigor- 
ously in order to carry more blood to the tissues. More 
oxygen is taken in by the lungs, and more heat is 
developed. Hence the skin, kidneys, and lungs have 
to do more work to get rid of the waste products. 

Breathing is mainly done by muscular action : thus, 
exercise causes the lungs to draw in an extra amount 
of fresh air, and to get rid of more impure air. Again, 
exercise stimulates the muscles which control the organs 
of digestion, thus giving a good appetite by creating a 
demand for food. 

In brief, muscular exercise is needed to keep the 
whole machinery of the body in good working order. 



58 YOUNG folks' physiology 

49. Amount of Physical Exercise. — Too much 
exercise, as well as too little, is a fruitful cause of ill- 
health. Exercise followed by fatigue, day after day, 
only does harm ; while judicious exercise with suitable 
rest is of great benefit. Hence the amount necessary 
to keep the body in the best order is a most important 
and practical question. 

It is laid down as a pretty safe rule, that a person of 
average height and weight, engaged in study or any 
other in-door or inactive business, should have an amount 
of exercise equivalent to a daily walk of five miles 
along a level road. Growing children, as a rule, take 
more exercise than this ; while most men in the prime 
of life, working in-door, take nothing like this amount ; 
and many women take less. Of course, if one's daily 

Health and strength contrasted. — " Health and strength are not 
synonymous terms, A person may have great strength in his limbs, or 
in certain muscles about the body, but really not have good health. It 
is altogether a mistaken idea to suppose that physical exercises have for 
their sole object the attainment of strength. There are other tissues 
and organs in the human system besides the muscular ; and the healthy 
action of the lungs and the stomach is far more important than great 
strength in the arms, legs, or the back. It is here, in this general exer- 
cise of all the muscles and parts of the body, that a well-regulated system 
of gymnastics has its great excellence. It aims to produce just that 
development of the human system upon which good health is permanently 
based, described by a distinguished writer as follows : ' Health is the 
uniform and regular performance of all the functions of the body, arising 
from the harmonious action of all its parts,' — a physical condition 
implying that all are sound, well-fitting, and well-matched. Some minds 
do not look far enough into life to see this distinction, or to value it if 
seen ; they fix their eyes longingly upon strength, — upon strength now, — 
and seemingly care not for the power to work long, to work well, to work 
successfully hereafter, which is health''' — Dr. Nathan Allen on 
Physical Culture. 



PHYSICAL EXERCISE 59 

work is active and out-door, no additional exercise is 
really necessary. Exercise may be varied in many 
ways, — the more ways the better. But, for the most 
part, it should always be taken in the open air. 

50. Time for Exercise The best time to take 

exercise is about two hours after a meal. The body is 
the weakest before breakfast. It is not best to do hard 
work, or take severe exercise, before this meal. Those 
who go to work or study before breakfast, should first 
eat half a slice of bread, or a cracker, or even drink a 
glass of milk, — just enough to "stay the stomach," 
and save the feeling of faintness, or "sinking" at the 
stomach. 

Just after a full meal, the stomach is busily doing its 
duty. Hence exercise at this time is apt to stop its 
action, and result sooner or later in dyspepsia. The 
evening is not the best time for exercise, because the 
body is tired after the labor of the day. It is useless 
to fix any exact rule. Ordinary work, or moderate 
exercise, as walking, is beneficial almost any time, 
except just after a full meal. 

51. Different Kinds of Physical Exercise. — The 
kind of exercise it is best to take depends very much upon 
one's daily occupation. Persons who sit at desks, stand 
at counters, or work in close rooms, as clerks, teachers, 
tailors, printers, etc., are prone to diseases due to lack 
of bodily exercise and to foul air. Every person should 
know, or be taught to know, his own needs and his own 
dangers. 

Almost every person should do some work, or take 
some exercise, with both body and mind every day. To 



60 YOUNG FOLKS' PHYSIOLOGY 

get and to keep vigorous health, it is not at all neces- 
sary to increase the size of the muscles very much, or 
do great feats of strength. Walking is the best of all 
exercises. It takes us into the open air and bright 
sunlight. It puts new life into many important muscles 
of the chest, abdomen, and limbs. With a brisk walk 
every day, taking care to keep warm and dry, no one 
need suffer from lack of proper exercise. Running, 
leaping, climbing, and other vigorous sports are well 
enough, especially for children, if they are not kept up 
too long, and do not cause fatigue. 

Violent sports, such as base-ball and foot-ball, are 
severe exercises, and occasionally dangerous. Rowing 
is admirably suited to most persons of either sex. 
Horse-back and bicycle riding, coasting, swimming, 
tennis, and skating are important helps to increase the 
bodily vigor. Certain sports also tend to beget self- 
reliance, coolness in danger, and a certain dignity and 
grace of person. There is hardly any one kind of 
exercise, which, taken alone, is able to give even toler- 
able development of all the muscles. Hence light 
gymnastic exercises are cheap and convenient means 
to develop muscles not used in work and games. 

Growing children should be trained every day at 
home or in school in the use of light wooden dumb- 
bells, light clubs or wands. A daily exercise of ten 
minutes will do much to develop feeble and narrow 
chests, to check the tendency to curvature of the 
spine and round shoulders so common with girls, and 
to give muscular strength and vigor to all parts of the 
body. 



PHYSICAL EXERCISE 6l 

52. Beneficial Effect of Physical Exercises in 
Schools. — The measure of the health of young people 
depends to a great degree upon a proper amount of 
physical training. Hence pupils should have some sort 
of physical exercises provided for them in the schools. 
This is especially true in large towns and cities, where 
there is less opportunity for out-door games. 

Such exercises, whether of one kind or another, 
should form a part of the regular course of study. The 
object aimed at should be the promotion of health and 
power of work, rather than the development of muscle 
or the doing of feats of agility and strength. 

Such exercises, if of real value, increase the breath- 
ing-power, and quicken the action of the heart. They 
fill the arteries with pure blood, and distribute it, with 
increased energy, to all the tissues and organs of the 
body, stimulating them to renewed activity. They re- 
invigorate the whole system, and at the same time 
furnish what is very important, — a pleasant recreation. 

To obtain the greatest amount of good from all move- 
ments calculated to improve the physical and mental 
strength of young people, it is highly important to re- 
member that pupils should be interested, and made to 
feel that these exercises are a recreation instead of a 
task. 

53. The Need of Physical Training in our School 
System. — Nearly one-half of the working hours of every 
pupil is spent in the schoolroom itself, or in the prepa- 
ration for the work there done. The conditions for the 
best physical development are rarely reached in our 
schools. 



62 YOUNG FOLKS* PHYSIOLOGY 

Impure air, lack of proper ventilation, faulty positions 
long continued, and other conditions unfavorable to 
health and normal development, demand a rest for the 
over-tired muscles and the over-taxed nerves. Hence 
the connection between physical training and school 
education is obvious. 

To the natural varieties of games and exercises used 
by boys — base-ball, foot-ball, bicycle, croquet, tennis, 
rowing — should be added systematic instruction in the 
schools. This should be especially directed with a 
view to develop the neglected and weak parts, and to 
add to the symmetry of the whole. 

The real benefit of systematic physical exercises in the 
schools, however, does not depend upon any large 
amount of development that they afford. They should 
be adapted to a harmonious development of the whole 
physical system, so as to result in a perfect control of 
every muscle, producing grace and freedom of move- 
ment, as well as health and vigor. 

Importance of Physical Development. — " In early boyhood and 
youth nothing can replace the active sports so much enjoyed at this 
period ; and while no'needless restrictions should be placed upon them, 
consideration should be paid to the amount, and especially to the charac- 
ter, of the games pursued by delicate youth. For these it would be better to 
develop the weakened parts by means of systematic physical exercises, 
by short excursions into the country, and by lighter sports. 

"Children who are taught at an early age to be obedient seem to en- 
joy more thoroughly such exercises as combine discipline with rhythmic 
movements; and consequently, the older the child, the more important it 
is to adopt a system of calisthenics, or light drill, or games that combine 
gymnastics with rhythmic sounds and periods of rest." — Dr. John M. 
Keating on Physical Development in Pepper's Cyclopaedia of the Diseases 
of Children. 



PHYSICAL EXERCISE 



63 



Simple exercises, without any apparatus, practised a few 
times every day for five or ten minutes at a time, do a 
great deal of good. They relax the tension of body and 
mind, and introduce an element of pleasure into the rou- 
tine of school life. These simple but vigorous and syste- 
matic movements are of great use in schools of the lower 
grades, and are widely used at present with a real benefit. 

54. The Various Systems of Gymnastics. — It is not 
the purpose of this book to discuss in detail the merits 
and defects of the various sys- 
tems of gymnastics now in 
general use in this country. 
They all have strong points — 
and their weak ones. 

The present revival of pop- 
ular interest in all that pertains 
to physical culture has stimu- 
lated our leading educators to 
renewed activity in urging a 
more systematic use of gymnas- 
tic exercises in our schools. 

We have sketched briefly in 
the following sections a few of the essential facts or prin- 
ciples that give character and utility to the two great 
systems (the Swedish and German) of gymnastic train- 
ing. Upon these two systems are based many of the 
valuable gymnastic movements now in common use in 
our schools. 

55. The Swedish System of Gymnastics. — The 
Swedish system of physical exercises as arranged by 
Ling, and modified to some extent by the teachers of 




wing' 



Fig. 31. — Showing the 
position (arms resembling the wings 
of a bird) in the Swedish drill. 



6 4 



YOUNG FOLKS' PHYSIOLOGY 



this method since his time, is generally regarded as 
having very important merits. The main principle 
which underlies all the movements of this system is 
to impart invigorating forces to the vital organs. 

Every movement is carried out with deliberation and 
mental attention, and designated by a phrase which can 
be used as a woi'd of command. This word of command 
is the only method, the advocates of this system claim, 
which enables the pupil to concentrate his mind on one 
thing at a time, that thing being his own movement. 

Words of command have 
other advantages. They 
teach the pupil to think 
quickly, to act as quickly, 
and to do a thing in the 
shortest possible time. 

Again, in the Swedish 
system regularity of 
method is adhered to very 
strictly. The exercises 
beginning by the very 
simplest, gradually be- 
come stronger and more complicated as the pupils 
develop. The slightest change of position — even the 
turning of a hand — has its recognized influence in the 
progression. 

The exercises of the Swedish system can be practised 
in the school-room, most of them by the class in con- 
cert, and equally by boys and girls. The method does 
not approve of music, and requires no apparatus. The 
exercises, not the apparatus, constitute the system. 




Fig. 32. — Showing the " rest " position (on 
account of its restful feeling) in the Swedish 
drill. 



PHYSICAL EXERCISE 



65 



<S> 



The movements can be made anywhere where there is 
sufficient floor-space to stand on and sufficient oxygen 
in the air. The apparatus can be easily adapted to the 
apparatus belonging to other systems, or to such simple 
means as ordinary chairs and 
desks, and other furniture. 
Though apparatus is desir- 
able, it is not absolutely 
necessary for good physical 
development, especially in 
gymnastics for children. 1 

1 " The exercises of the Swedish 
system are chosen according to their 
gymnastic value, which quality depends 
on how the movement combines the 
utmost effect on the body with sim- 
plicity and beauty of performance. 
Only such exercises are used whose 
local and general effects are fairly well 
known and proved to be needed by 
the body. Not only the needs of the 
individual, but his abilities as well, 
are to be taken into consideration ; 
and for that reason the teacher must 
know how to vary the exercises ac- 
cording to the degree of physical cul- 
ture possessed by the pupil. The 
movement should have its developing 
effects in a short time ; it should be 
simple, SO that every pupil can do it Swedish system, ready for gymnastic drill, 
fairly well ; and it should have beauty of execution, according to each 
one's ability." — Baron Nils Posse, M.G. 

Note. — For a most comprehensive work on the Swedish system, the 
teacher is referred to the " Swedish System of Educational Gymnastics," 
with 264 illustrations, by Baron Nils Posse, M. G., Director of the Posse 
Gymnasium, Boston. A small manual for teachers, called " Handbook 
of School Gymnastics of the Swedish Systems," by Baron Nils Posse, 
has been recently published. 




33. — Standing position in 



66 YOUNG folks' physiology 

56. The German System of School Gymnastics. — 

The German system of gymnastics ranks high among all 
the different systems. It has been built up during 
almost a century by men of science. It is practised in 
classes at school by hundreds at the same time, and 
by single persons as home exercises. 

The Benefits derived from a Modern Gymnasium. — a I think it 
will be admitted by all thoughtful persons that one-half the battle for 
mental education has been won when you arouse in a boy a genuine love 
for learning. So one-half the struggle for physical training has been 
won when he can be induced to take a genuine interest in his bodily 
condition, — to want to remedy its defects, and to pride himself on the 
purity of his skin, the firmness of his muscles, and the uprightness of 
his figure. 

" Whether the young man chooses afterwards to use the gymnasium, 
to run, to row, to play ball, or to saw wood, for the purpose of improv- 
ing his physical condition, matters little, provided he accomplishes that 
object. 

"The modern gymnasium, however, offers facilities for building up the 
body that are not excelled by any other system of exercise. The intro- 
duction of the new developing appliances has opened up the possibility 
of the gymnasium to thousands to whom it was formerly an institution 
of doubtful value. 

" The student is no longer compelled to compete with others in the 
performance of feats that are distasteful to him. He can now compete 
with himself — that is, with his own physical condition — from week to 
week, and from month to month. If he is not strong enough to lift his 
own weight, the apparatus can be adjusted to a weight he can lift. If he 
is weak in the chest or the back, he can spend his time and energy in 
strengthening inose parts without fear of strain or injury. 

" In fact, he can work for an hour, going from one piece of apparatus 
to another, keeping always within the circuit of his capacity, and adding 
slowly and surely to his general strength and powers of endurance. If 
the heart is weak, the lung-capacity small, the liver sluggish, the circu- 
lation feeble, or the nervous system impaired, etc., special forms of 
exercise can be prescribed to meet these conditions." — Dr. D. A. Sar- 
gent, Director of the Hemenway Gymnasium, Harvard University. 



PHYSICAL EXERCISE 



6 7 



The instruction begins with simple and easy move- 
ments, and gradually proceeds to those more difficult. 
The apparatus used in school practice is not compli- 
cated or expensive. It may be omitted altogether if the 
necessary room for climbing- 
poles, ladders, and some light 
apparatus cannot be provided 
for. An almost endless variety 
of simple and complicated free 
exercises may be made, with or 
without the common hand ap- 
paratus, as wands, dumb-bells, 
and Indian clubs. 

In the German schools the 
lessons begin regularly with a 
series of free and order exercises. 
Every scholar has to take part in 
them. The rhythmical order in 
which they are produced calls for 
absolute attention, and allows 
no backwardness. Class exer- 
cises on apparatus follow the free 
exercises. A change of appara- 
tus takes place, and then the 
lesson ends with some exercises . 
left to individual inclination. . FlG ' 34 -~ A school s irl in ^ mnas - 

tic costume. 

57. The System needed for 
our Schools. — The various systems of physical exer- 
cises as practised in Europe have proved acceptable 
in this country, but with many important modifica- 
tions. American educators have ideas of their own on 




68 YOUNG folks' physiology 

physical culture. We are slow to adopt the methods of 
other countries unless they are modified to suit our 
special demands. 

Many of our ablest teachers of physical exercises 
believe in music in gymnastic training. They claim 
that many of the lighter exercises can be better exe- 
cuted with music. 

It is also maintained that it is no relief from the 
strain on the brain to go from the study of arithmetic 
to the performance of physical exercises that demand 
close attention to the teacher who gives the signal for 
the gymnastic exercises. 

In brief, the ideal system adopted for our schools 
must be an eclectic one. It will assimilate all that is 
best in every known method. It is not the system 
itself which must bear the test of criticism, but the way 
in which the system is taught. 

58. Effect of Alcoholic Liquors and Tobacco on 
Physical Exercise. — The main object of physical ex- 
ercise is to get our bodies into such a condition, and to 
keep them in that condition, whereby the average 
amount of working-power can be utilized at any time 
without harm to the bodily health. To keep up this 
amount of physical power and endurance we must be 
obedient to certain great laws of health. 

One of these laws which never can be violated with 
impunity is that which forbids the use of alcoholic 
liquors and tobacco. Strong drink and tobacco will 
put to naught the most elaborate and costly system of 
physical training. 

Those who train athletes, base-ball and foot-ball 



PHYSICAL EXERCISE 69 

players, oarsmen, and all others who take part in severe 
physical contests, understand this, and rigidly forbid 
their men to touch a drop of alcoholic drink, or even to 
smoke or chew tobacco. Experience has proved beyond 
all doubt that strong drink is a positive injury, either 
when men are in training for or undergoing contests 
demanding long-continued physical endurance. 

The same law holds good in the ordinary physical 
exercises of every-day life. Alcohol and tobacco act as 
poisons to the nerve-force which controls the muscles, 
and thus lessen the amount of muscular power and 
endurance. 

The demands of modern life call for a sound body 
rather than a strong body. Neither is possible to those 
who indulge in alcoholic drink or tobacco. 

Note. — In the Appendix may be found a series of simple gymnastic 
exercises, systematically arranged, which may serve as the basis of 
other and more extended exercises suitable for every-day use in the 
schoolroom. 



70 YOUNG FOLKS PHYSIOLOGY 



CHAPTER V 

FOOD AND DRINK 

59. Work, Waste, and Repair. — The body is in 
some ways — as we have learned in the Introduction — 
very much like a steam-engine. The bones and mus- 
cles correspond to the machinery. The motive-power 
is furnished by the food we eat. The food is to us 
what coal and wood are to the engine. 

Like the locomotive, our bodies move about, and 
are warm, because a slow fire is always burning in 
them. This fire, like that of the engine, needs fresh 
fuel from time to time. The food we eat becomes 
part and parcel of the body, and it is the whole body 
that is slowly burning. In order to keep up this bodily 
burning, we must have oxygen. Without fuel and air, 
the fire in the engine will go out. 

So it is with the fire in the body. Without food 
and air, the combustion of our bodies would soon flag, 
and we would soon die for want of them. When coal 
or wood is burned, we get ashes. When food is burned 
in the body, we get, not exactly ashes, but something 
like it, which is got rid of as useless substances. 

Again, the steam-engine wears out, and needs repair 
from time to time. So it is with our bodies. There is 
wear and tear constantly in every part. Every beat of 



FOOD AND DRINK J\ 

the heart, every contraction of a muscle, and even 
our very thoughts, lead to waste. Every time 
we think, look, speak, or move, we do so at the 
expense of some minute portion of the tissues of the 
body. 

60. Why we need Food. — To make good this 
waste, there must be something taken into the body, 
or it soon suffers. The body is constantly wearing 
away, and must be constantly built up again. Hence 
we see the necessity for food. The food, too, must 
contain the same things that the body has lost. 

The blood is the stream which carries this material 
for restoring the waste tissues of the body. Indeed, 
we may say that the blood is that material itself. It is 
simply the food we have eaten, in another form. Food 
must be of such a kind, and in such a quantity, as to 
supply an amount of nutriment to the tissues equal 
to the waste which takes place. 

During early life, when the body is growing rapidly, 
more of tissue-food is needed than in adult life, when 
repair alone is called for. When the body has been 
wasted by disease, as typhoid fever for instance, much 
tissue-food is needed to repair the waste, and to restore 
the muscles to their former size and vigor. 

If but little or no food be taken, or if it be not of the 
right sort, the body slowly loses in weight. If we try 
to do without food, we grow chilly and cold, feeble, 
faint, and too weak to move. A point will at length be 
reached at which death from starvation must take 
place. The bodily fire has gone out, and nothing but 
cold ashes is left. 



J2 YOUNG FOLKS PHYSIOLOGY 

61. Different Classes of Food. — For convenience 
let us divide foods, or foodstuffs, in four great classes : — 

I. Nitrogenous Foods, or Albumens. 
II. Starches and Sugars. 
III. Oil and Fats. 
IT. Inorganic or Mineral Foods. 

62. Nitrogenous Foods, or Albumens. — These 
foods, sometimes called flesh-forming foods, contain, 
as their name implies, all the materials requisite for 
restoring the tissues. They contain all four elements, 
— nitrogen, carbon, oxygen, and hydrogen. They are 
especially rich, however, in nitrogen, which forms an 
essential part of the animal tissues. 

These foods are called albumens, because they con- 
tain a certain white substance known as albumen, 
familiar to all as the white of an egg. Lean meat ; the 
cheesy part, or curd, of milk; pease and beans, — are 

The Wear and Tear of the Body. — "In the physical life of man 
there is scarcely such a thing as rest : the numberless organs and 
tissues which compose his frame are undergoing perpetual change, 
and in the exercise of the function of each, some part of it is destroyed. 
Thus, we cannot think, feel, or move without wasting some proportion, 
great or small, according to the energy of the act, of the apparatuses 
concerned, — such as brain, nerve, or muscles. Xow, this waste-product 
cannot remain in its original situation, where it would not only be use- 
less dross, but also obstructive and injurious. Such old material is 
being daily removed from our bodies to the average amount of three or 
more pounds ; and that an equal quantity of new shall take its place is 
the first principle of alimentation. This tissue-change is so complete, 
that not a particle of our present body will be ours a short time hence ; 
and we will be, as I have lately seen it phrased, like the knife which, 
after having had several new blades, and at least one new handle, was 
still the same old knife to its owner." — Mapother's Lectures on Public 
Health. 



FOOD AND DRINK 73 

rich in albumen. Wheat, barley, oats, and maize also 
contain albumen. 

A well-known group of plants with seeds enclosed in 
pods, or legumes, hence called "legumens," is rich in a 
nitrogenous substance, resembling the albumen of eggs 
and the gluten of flour. Pease, beans, and other vege- 
tables of this group, are nutritious on account of this 
flesh-forming material. 

63. Starches and Sugars. — The starches and 
sugars contain carbon, hydrogen, and oxygen, but no 
nitrogen. They are sometimes called the "sugar 
hydrocarbons." As their proportions of hydrogen and 
oxygen are the same as in water, we may consider 
them as carbon or charcoal dissolved in water. 

This class of foodstuffs forms a large proportion of 
all those plants which are generally used as food. 
Wheat, barley, oats, rye, rice, maize, tapioca, arrow- 
root, sago, potatoes, etc., are rich in starch. In fact, 
starch stands first in importance among the various 
vegetable foods. Starch in its natural state would be 
useless as food, because it is insoluble. It is only after 
it has been acted upon by the digestive fluids, and con- 
verted into sugar, that it becomes soluble, and is 
capable of being taken up by the blood. 

The sugars themselves come from the fruits and 
vegetables, honey, and milk. The sugars serve as a kind 
of fuel, which is burned up by the oxygen in the body. 
The combustion of these fuel-foods develops and keeps 
up the necessary heat of the body, and the vital energy 
or strength which enables us to perform our various 
duties. 



74 YOUNG FOLKS PHYSIOLOGY 

64. Oil and Fats. — These foods contain carbon, 
hydrogen, and oxygen. They are sometimes called the 
"fatty hydrocarbons." This class of foods is derived 
from the fat of meat, eggs, butter, and milk, also from 
the various oils. Most of the breadstuffs contain more 
or less of fat or oil. The oils and fat supply about 
twice the amount of energy, whether manifested as heat 
or motor force, as that afforded by the combustion of 
an equal amount of starch or sugar. 

65. Inorganic Substances, or Mineral Foods. — 
Organic substances, such as those included in the food- 
stuffs just described, are derived from living forms, as 
animals and vegetables. Besides these, the body de- 
mands a certain amount of inorganic substances, derived 
from the mineral kingdom. These are water, salt, iron, 
lime, magnesia, phosphorus, and potash. Except water 
and common salt, these substances generally enter the 
body only in combination with other foodstuffs. 

66. Extra Foods, or Appetizers. — A vigorous appe- 
tite requires little else besides salt for an appetizer. 
Salt has been and is universally used by all animals and 
peoples. Salt has always been the symbol of life, hospi- 
tality, and wisdom. Animals will travel for miles to 
reach salt-licks, while men have risked their lives to get 
even a taste of salt. Pepper, mustard, ginger, and 
other heating appetizers, are used to give flavor to taste- 
less foods, and to stimulate the sense of taste, and to in- 
crease the flow of saliva and gastric juice. So long as 
the "appetite comes with eating," and ordinary food is 
enjoyed, the use of these stimulating appetizers is un- 
necessary, and becomes simply a matter of habit. 



FOOD AND DRINK 75 

67. Different Articles of Diet. Vegetable Food. — 

The most important food of this class is bread, "the staff 
of life." There is no single food in the world which meets 
so many necessary wants of the body. Bread is made 
from the flour of many kinds of seeds, such as oats, rye, 
Indian corn, etc. But in this country it is nearly 
always made from wheat. 

Wheat-flour gives us starch, sugar, gluten, — a form of 
albuminous food. Hence wheat has nearly everything 
to support life except fat. When we eat bread and 
butter, we have nearly a perfect food. Corn-meal is rich 
in nitrogen, and has much oily matter. It is highly 
nutritious and a cheap article of food. Oatmeal is 
richer than flour in nitrogen and fat, and is therefore 
more nutritious. Rice, though rich in carbon, is one of 
the least nutritious of all the cereals. Pease and beans 
contain more nitrogen than any of the cereals, and are 
as rich in carbon as wheat-flour. 

The common, or Irish, potato is a most important 
article of diet. Although it is more than two-thirds 
water, and has little nutriment, yet it is easily digested, 
— a cheap and economical article of diet. Ripe fruits, 
such as apples, pears, peaches, melons, grapes, oranges, 
etc., though not of much nutritious value, are prized 
for their agreeable flavor. Sugar and molasses are both 
largely used in cooking. Their nutritious value is 
about the same as that of starch. 

68. Animal Food. — The first place must be given to 
milk, for it is the food of all others which gives us 
nourishment in the simplest and best form. It con- 
tains a large quantity of water, caseine, together with 



j6 YOUNG FOLKS' PHYSIOLOGY 

sugar and fat. Eggs have a large amount of nutriment 
in a small space. Two-thirds of an egg is water, the 
rest albumen and fat. Eggs are cooked in many ways, 
and are generally easily digested. 

Meats, for the most part, consist of the muscles of 
the various animals. The most common are beef, mut- 
ton, lamb, veal, and pork. Meat is rich in albumen, and 
has more or less of fat. It is a most common and 
important article of diet, and, as a whole, is easily 
digested, except, perhaps, veal and pork. Fish is at 
once a cheap, abundant, and nourishing food. Poultry 
is a useful, light article of food, especially for the sick 
and feeble. The flesh is easy to digest, and gives a deal 
of nourishment. 

69. Mineral Food. — Water is a mineral food, which 
will be described hereafter. There is about a half a 
pound of common salt in the body at any one time. 
But we are continually losing it. Tears, we know, con- 
tain salt ; and it is also found in the sweat. Many 
people think they do not eat any common salt, because 
they do not take it by itself ; but they forget that 
many of the foods they eat, such as bread and meat, 
have a little of it. 

The salts of potash are chiefly found in the vege- 
tables we eat, especially lettuce. These salts help 
purify the blood. The salts of lime make the bones 
hard and strong. Iron is contained in very small quan- 
tities in many of the foods we eat. It helps to make 
good blood. 

70. Natural Drink. Pure Water. — Drink is of just as 
much importance as food. Every one knows what hap- 



FOOD AND DRINK JJ 

pens to plants when they are deprived of their drink. 
They first droop, and then, soon afterwards, wither and 
die. So also it is with all animals. If they are 
deprived of their drink, they also droop, and at last die. 
Animals may be dried away into death as certainly as 
plants. 

Drink is the agent which has been provided by 
nature to wash the food into and through the living tis- 
sue of bodies. The drink provided by nature for all 
living creatures is pure water. Wild animals, as well as 
domestic, often take no other drink but water. 



The Value Of Salt. — In most countries, salt is "cheap as dirt;" 
while in parts of Africa it is worth its weight in gold. In that land 
brothers will barter their sisters, husbands their wives, and parents their 
children, for salt. On the Gold Coast of Africa a handful of salt is the 
most valuable thing upon earth after gold, and will purchase a slave or 
two. Travellers tell us that with certain tribes the use of salt is such a 
luxury that to say of a man, " He flavors his food with salt," is to imply 
that he is rich ; and children will suck a piece of rock-salt as if it were sugar. 
In India a large revenue is raised from the salt-tax, salt being something 
which even the poorest native will buy. In old times untold tortures were 
inflicted upon prisoners in Holland, by feeding them on bread alone, made 
without salt. No stronger mark of respect or affection can be shown in 
some countries than the sending of salt from the tables of the rich to 
their poorer friends. In the Book of Leviticus it is expressly com- 
manded, as one of the ordinances of Moses, that every oblation of meat 
upon the altar shall be seasoned with salt, without lacking ; and hence it 
is called the Salt of the Covenant of God. The Greeks and Romans 
also used salt in their sacrificial cakes. Everywhere, and almost always, 
indeed, salt has been regarded aS emblematical of wisdom, wit, and immor- 
lality. To taste a man's salt, was to be bound by the rites of hospitality ; 
and no oath was more solemn than that which was sworn upon bread and 
salt. To sprinkle the meat with salt was to drive away the Devil ; and to 
this day, among the superstitious, nothing is more unlucky than to spill 
the salt. 



78 YOUNG folks' physiology 

Thousands of human beings, following the example 
of the lower animals, drink nothing but water, but yet 
toil long and hard, and fulfil all the duties of a reason- 
able and intelligent existence. 

In brief, it is clearly evident that pure water is the 
only drink that is absolutely essential for all the pur- 
poses of life. 

Now, it is plain that if we take a quart or more of 
drink every day, nearly an equal amount must be 
thrown out daily from the body. This is really the 
fact. Some portion of it steams away with the breath. 
More of it passes through the pores of the skin, and 
still more is drained away through the kidneys. Water 
thus drains off a great deal of waste and refuse matter 
that the body must get rid of. Water therefore drains 
waste matters out of the body at the same time it 
washes nourishing foods into it. 

To be suitable for diet, water should be clear, with- 
out color, with little or no taste or smell, and free from 
any great amount of animal or vegetable matter. Real 
pure water does not occur in nature. Rain-water is 
the purest if properly collected. Well and spring water, 
and that brought into towns from some distant pond or 
river, all contain more or-less mineral matter. The vari- 
ous mineral-spring waters, such as those at Saratoga, 
popularly used as medicines, are highly charged with 
mineral substances. 

71. Artificial Drinks. — Our great natural drink, as 
we have learned, is pure water. Milk is also a natural 
drink. We have already learned some things about 
milk and water. Now, man has always contrived many 



FOOD AND DRINK 79 

ways to flavor his drink in some way or other. The 
greater portion of almost every drink is water ; but, in 
various ways, other substances are mixed with the 
water, to give it a pleasant taste. Such drinks are arti- 
ficial. Tea, coffee, and cocoa are the more common 
artificial drinks. 

Tea was first brought to England about two hundred 
and fifty years ago, but it did not come into general 
use. The tea-plant is chiefly cultivated in China. 
When boiling water is poured on the dried leaves, a 
substance which chemists call an " active principle," 
and known as theine, is dissolved. The liquid so 
obtained is called a " decoction," and makes the com- 
mon drink known as tea. 

Coffee comes to us mainly from the West Indies, Ara- 
bia, South America, and the East Indies. When boil- 
ing water is poured on ground coffee, it dissolves a 
substance called caffeine,, very much like the theine of 
tea. 

The cocoa, or chocolate, tree is a native of tropical 
America. It has an active principle which resembles 
theine and caffeine. 

Chocolate is cocoa ground up with sugar and certain 
spices. 

One of the most common of all artificial drinks used 
in this country is ice-water. The temptation to drink 
freely of it in hot weather is rarely resisted. Ice-water 
quenches the thirst only for a moment. . It weakens 
the strongest stomach after a time, and is thus a com- 
mon cause of dyspepsia. If one must drink it, sip a 
little slowly. 



80 YOUNG FOLKS' PHYSIOLOGY 

The most common of all artificial drinks are alcoholic 
liquors. 

In the next chapter we shall learn a great deal about 
their origin and nature. 

72. The Effect of Drinking Tea and Coffee. — There 
is rarely any necessity for one to drink tea or coffee. 
They have little or no value as foods. Some per- 
sons cannot drink even a single cup of coffee or tea 
without feeling the worse for it : headache, indigestion, 
heartburn, wakefulness at night, and constipation are 
the most common after-effects. Strong tea should 
never be used. 

Hard-working women and others, from choice or 
necessity, too often make their meals of dry toast and 
several cups of strong tea. Drank in excess, tea may 
weaken the action of the heart, and produce the pecul- 
iar beating, after much exertion, known as "palpita- 
tion." Hence we have "the tea-drinker's heart." 
Coffee and tea are unsuitable articles of diet for grow- 
ing children. 

Drinking strong coffee often gives a muddy look to 
the complexion of young folks ; much tea-drinking 
imparts a parchment appearance to the skin of young 
women. Doubtless all of us would be in better health 
if we never drank another drop of tea or coffee. 



ORIGIN AND NATURE OF FERMENTED DRINKS 8 1 

CHAPTER VI 

ORIGIN AND NATURE OF FERMENTED DRINKS 

73. Decay a Law of Nature. — If one is thirsty 
and cannot get water to drink, his thirst can be 
greatly relieved by juicy fruits. Fruit-juices are com- 
posed largely of water, sweetened with sugar, which 
nature prepares in them as the fruit ripens, and flavors 
each according to its kind. Such juices, as they come 
fresh from the fruit, are healthful. 

But suppose the fruit is crushed, and the juice is 
drawn off and left standing in air of ordinary tempera- 
ture. How long will it remain a healthful drink ? Only 
a very few hours. 

All animal and vegetable matter is composed of vari- 
ous simple substances, gases, liquids, and solids. Nature 
has provided that when plant or animal matter ceases 
to live, these different substances composing it shall be 
set free for use again in forming new combinations. 
When we see meat spoiling, bread or cheese moulding, 
fruit rotting, or sauce turning sour, we see simply an 
example of this provision. 1 

The "working," or fermenting, of sweet fruit, plant, 
or other vegetable juices, which takes place very soon 
after they are pressed out, is another example of the 
same wise provision. This last process is not accom- 
panied by foul-smelling odors, as are most of the others, 
but by a peculiar bubbling of the liquid caused by the 

1 See Note 4, page 358. 



52 YOUNG FOLKS' PHYSIOLOGY 

escaping gases ; hence the name " fermentation," from 
the Latin meaning " to boil" 

fermentation in its widest sense includes the changes 
going on in the putrefying meat, the moulding cheese, 
and the rotting fruit, as well as in the fermenting fruit- 
juice. They are all forms of decomposition that set 
free the simpler substances composing animal and vege- 
table matter. For all these one law holds good. I: is 
this : — 

Fermentation entirely changes the nature of 

zzz sue5zan3z jzzmznzzz. 

74. The Cause of Decay. — What causes all these 
various processes of decomposition ? Are plants and 
animals so constructed that when they have served 
their purpose they fall to pieces of themselves, or from 
the action of the air, as was once supposed ? No : the 
microscope has introduced to us whole tribes and fam- 
ilies of minute living forms whose special work is to 
cause this decomposition of the dead bodies of their 
neighbors. 

Were it not for these the whole surface of the earth 
would in time be covered with dead trees and other life- 
less bodies, and there would be no simple substances left 
out of which to build up new ones. 

Among these minute living forms are some that do 
not even wait for a plant or animal to die before attack- 
ing it. Such are the disease germs invisible to the 
naked eye, lurking in the air we breathe and in the water 
we drink, ready to cause sickness if given a lodgement. 



ORIGIN AND NATURE OF FERMENTED DRINKS 83 

Many kinds of these have been studied and described 
and grouped under the family name of Bacteria, the 
lowest of the plant-families. 

The decay of meat and the souring of milk are caused 
by minute plant-cells belonging to this family. To an- 
other family low down in plant-life, viz., the fungi, 
belong the moulds that spoil our bread and cheese, and 
cause our sauce to sour and our fruit to rot. 1 

75. Ferments and Their Work. — To the fungi 
family also belong the class of microscopic plants 
called Ferments that cause the fermentation of sweet 
fruit, plant, or other vegetable juices. As long as fruit- 
juice remains inside the fruit, the ferment germs float- 
ing in the air, and even resting on the skins and stems 
of the fruit, do not enter it. 2 

When apples are ground to make • cider, or grape- 
juice is pressed out to make wine, the ferments resting 
on their surfaces are washed into the expressed juice. 
Each ferment rapidly produces others, unless the liquid 
is kept at a very cold temperature, and all begin at once 
to break up the sugar of the juice. 3 

Two substances set free by this decomposition of the 
sugar are carbonic acid gas, which may be seen coming 

1 See Note 5, page 359. 

'"Fermentation is the consequence of a development of vegetable cells, the 
germs of which do not exist in the saccharine juices within the fruits." — Pas- 
teur's Studies in Fermentation. 

8 " In the fermentation of natural saccharine juices, which, especially when 
acid, undergo a decided alcoholic fermentation, the ferments originate in certain 
germ-cells which are spread in the form of minute spherical bodies of a yellow or 
brown color, isolated, or in groups, over the exterior surface of the epidermis 
of the plant, and which are gifted with an extraordinary power of budding 
with ease and rapidity in fermentable liquids." — Pasteur's Studies in Fermen- 
tation. 



84 YOUNG folks' physiology 

up out of the liquid in tiny bubbles, and alcohol, a poison 
which remains in the liquid. 

The whole nature of the fruit-juice, which was whole- 
some and beneficial before this fermentation took place, 
is now changed by the presence of the alcohol. It be- 
comes a poisonous liquid, called cider if made from 
apple-juice; wine if made from the juice of grapes, 
berries, currants, and other fruits. 

If man should then leave this fermented liquid to 
itself, other kinds of ferments would enter it, and carry 
on the process of decomposition by setting up other 
kinds of fermentations, each after its own kind. For 
every fermentation, it must be remembered, has its own 
special ferment. 

Among the minute plant-cells belonging to the bac- 
teria family is one whose special work is to change the 
alcohol of a fermented liquid to acetic acid. Thus the 
fermented juice becomes vinegar, which contains no 
alcohol. Left again to itself, other forms of the bacte- 
ria enter the vinegar, causing still further changes, until 
finally the water is all evaporated and nothing but a 
little earthy matter is left. The work of decomposition 
is then finished. 

But man interferes. He prevents, if possible, the 
microbe of vinegar from entering the fermented fruit- 
juice that he may use it for a drink. In many cases he 
is ignorant of the nature of the poison which the fer- 
ments produced by destroying the sugar. 

76. Alcohol as a Poison. — Any substance capable, 
when absorbed into the blood, of injuring health or de- 
stroying life, is a Poison. Alcohol is capable of destroy- 



ORIGIN AND NATURE OF FERMENTED DRINKS 85 

ing life when taken in sufficient quantities, as has been 
proved by numerous instances of death following the 
drinking of spirits on a wager, or a draught of brandy or 
gin taken in ignorance by a child. 

Alcohol is also capable of injuring health, as is proved 
over and over again every day. Few people have not 
known of one or more cases of loss of health from this 
cause, while physicians are meeting them constantly. 1 

Remember this : 

Alcohol is a Poison. 

It is classed as such in standard treatises on poisons, in 



Alcohol a Poison. — " Alcohol is universally ranked among poisons 
by physiologists, chemists, physicians, toxicologists, and all who have 
experimented, studied, and written upon the subject, and who, therefore, 
best understand it. It is not necessary to the action of poisons that they 
be always swallowed in fatal doses." — Professor W. J. Youmans. 

Is alcohol a poison ? I reply, yes. It answers to the description of a 
poison. It possesses an inherent, deleterious property, which, when in- 
troduced into the system, is capable of destroying life, and it has its place 
with arsenic, belladonna, prussic acid, opium, etc. In its effects upon 
the living system alcohol is first an irritant, and afterward, when it has 
entered the circulation, it becomes a narcotic. Were alcohol an irritant 
only, a man would as soon poison himself with arsenic. The narcotic 
element is the Siren that leads him on to ruin and to death." — Dr. Wil- 
lard Parker. 

" Alcohol is classed among the poisons by medical writers on poisons. 
I do not know of an exception among physicians. Lt is ranked among 
the poisons from its effects on the body analogous to those of the other 
poisons. What is said of the effect of alcohol must be true of all doses, 
large or small, although the effect of very minute doses may be imper- 
ceptible. Arsenic may be administered in doses so small as to produce 
no apparent ill effects; yet no one doubts that arsenic is a poison. . . . 
If a person dies of delirium tremens, it is not the last glass that kills him, 
but every dose or glass he has taken in his life has conduced to the 
result." — Dr. Reuben D. Mussey. 

1 See Note 6, page 361. ' 



86 YOUNG folks' physiology 

medical dispensatories, and by eminent medical writers 
too numerous to mention. 

Certain poisons whose action is to deaden or paralyze 
the brain and nerves are called narcotic poisons. Alcohol 
is classed by the authorities among the narcotic poisons, 
because of its paralyzing effect on brain and nerve sub- 
stance, of which we shall learn later. 1 

77. The Alcoholic Appetite. — A celebrated physician 
has said, " If a person eats bread three times a day for 
twenty years he is just as readily satisfied at the end of 
the time as he was at the beginning. Natural appetite, 
or hunger, is simply the demand for material to supply 
the growth or waste of tissue. Every substance capable 
of assimilation will satisfy that demand, and with that sat- 
isfaction ceases, for the time being, all relish for more." 

This is not the case with alcohol. Its worst charac- 
teristic is its power to set up a perpetual craving for 
itself, which calls for repeated and increasing amounts, 2 
This is called the alcoholic appetite. All natural appe- 
tites have natural limits. But the appetite for alcohol, 
created by the diseased conditions which it has itself 
produced, has no natural limit. 

From the first glass of the boy just beginning to 
drink to the dram of the drunkard whose tissues are 
poisoned and inflamed by it, its nature is ever to excite 
a thirst for more. Whether it is drank in the form of 
wine, beer, cider, rum, or whiskey, its character is the 
same ; for the character of any substance depends upon 
its quality, not its quantity. The secret of the drunkard's 
craving for alcohol is in the nature of the drink, rather 
than in the weakness of the drinker. 

1 See Note 7, page 362. a See Note 8, page 363. 



ORIGIN AND NATURE OF FERMENTED DRINKS 8? 

There is a scientific connection between the first glass 
and the drunkard's fate. No one is safe who begins to 
take any liquor containing alcohol. Entire abstinence 
is the only safeguard against forming the alcoholic 
appetite, and the only cure for it when it is formed. 

Because of the ease with which the alcoholic appetite is 
roused where it has been once formed, and the power of 
a little to form such an appetite, no liquor containing 
alcohol should ever be used as a flavoring for pies, pud- 
ding-sauces, jellies, or any other article of food. 1 

The habit of treating one's friends to beer, wine, or any 
other alcoholic drink, is simply asking them to poison 
themselves at our expense. Such treating is a mark 
of ignorance rather than an evidence of real courtesy 
or friendship, and must be so considered by one who 
understands the true nature of such substances. 

Furnishing wines or liquors at parties, dinners, or 
other entertainments, or for guests or callers, is virtu- 
ally offering poisonous drinks, and is never an act of 
true or intelligent hospitality or real kindness. It may 
be placing temptation too strong to be resisted in the 
way of an inherited or acquired appetite for alcohol. 

78. Cider. — The fermented juice of apples, known as 
cider, contains alcohol varying in amount with the length 
of time it is allowed to ferment. When cider remains 
in air of the ordinary temperature, alcohol can usually 
be found in it in about six hours from the time it comes 
from the press, sometimes sooner. The power which 
alcohol has to create an appetite for itself makes a bev- 
erage containing it in any quantity an unsafe drink. 

As cider grows older it is said to be growing hard ; i.e., 

1 See Note 9, page 365. 



88 YOUNG folks' physiology 

the amount of alcohol in it is increasing. Hard cider 
often contains ten per cent of alcohol. If a person 
begins, when the barrel of cider is first put in the cellar, 
to drink one or two glasses every day, and continues the 
same amount daily as the cider grows hard, he is every 
day getting more and more alcohol, which, besides be- 
numbing his brain, hardening his heart, and spoiling his 
temper, has the power to create the craving that nothing 
but alcohol, in ever-increasing amounts, will satisfy. 

Note this : Many drunkards have acquired the ap- 
petite for strong drink at the cider-barrel. 

79. Wine. — Wine is made chiefly from the juice of 
grapes. It can be made from the juice of berries, cur- 
rants, and other fruits. Drinks called home-made wines 
are frequently made from such fruits. But the ferments 
that produce alcohol are in the air and on the skins of 
the fruit ready to set up the pocess of fermentation as 
soon as their juices are pressed out. They cannot get 
inside the whole fruit to make alcohol, hence we are 
in no danger of being injured by alcohol when we take 
our fruit-juices fresh from the fruit itself. 

Some wines called "light wines " contain a smaller 
amount of alcohol than others ; but even the lightest 
wines contain alcohol enough to make them dangerous 
drinks. The power of alcohol to create an appetite for 
more does not change with the quantity. 

The theory that the use of light wines will prevent the 
use of stronger drinks, and so diminish drunkenness, 
is disproved by the history of countries where such 
wines have come into general use. Where the alcohol 
in the light wines does not lead to a use of stronger 



ORIGIN AND NATURE OF FERMENTED DRINKS 89 

drinks, enough more of the weaker drink is taken to pro- 
duce an equal amount of drunkenness. Almost whole 
communities, including men, women, and children, in 
some wine-making districts, will be in a continual state 
of drunkenness during a large part of the vinting season. 1 

80. Beer. — Certain of the fermented drinks are called 
"malt liquors." These are beer, ale, and porter, which 
are made from barley and other grains. The starch of 
the grain is turned to sugar by keeping the grain 
warm and moist until it is sprouted. Heat is applied to 
kill the sprouts ; and the grain, then called malt, is 
ground or mashed, and soaked in water. To the sweet 
liquid thus obtained is added yeast, which is a kind of 
ferment, and hops. The yeast sets up vinous fermen- 
tation, which changes the sugar of the wort to alcohol 
and carbonic acid gas. The gas escapes in bubbles, pro- 
ducing a froth on the top of the fermenting-vat. The 
alcohol does not escape : it remains in the beer, mak- 
ing it a poisonous drink. 

Beer is responsible for many crimes. It seems to 
have a benumbing effect upon the moral nature that 
prepares the drinker for wicked and cruel deeds and for 
deliberate crime. 2 A copious beer-drinker often looks 
the very picture of health, and boasts of the healthful- 
ness of his favorite beverage ; but the testimony of 
physicians, surgeons, and life-insurance companies is 

1 See Note 10, page 365. 
a " Beer and wine do not give strength for work, but, on the other hand, often 
make people dull, heavy, stupid, and unfit for work. The most severe and con- 
tinued work can be performed without them, and there are now some millions of 
people in this country who never taste them. Happy will be the day when they 
are not drank by any, but particularly by the workingman, who finds it difficult to 
maintain his family. Then will there be less quarrelling, poverty, and crime, 
and more food, clothing, and education." — Dr. Edward Smith of London. 



gO YOUNG FOLKS* PHYSIOLOGY 

that the beer-drinker, of all others, is most liable to 
swift and sudden death from some slight causes. 1 

The surgeon dreads him for a subject, for his blood is 
often in such a state that a slight cut may develop into a 
gangrenous wound that ends quickly in death. A slight 
cold brings on a fatal pneumonia in spite of the best 
physician's efforts. The president of a leading life-in- 
surance company said once of this class of drinkers : — 

" It was as if the system had been kept fair outside, 
while within it was eaten to a shell, and at the first touch 
of disease there was utter collapse : every fibre was 
poisoned and weak. And this, in its main features, 
varying, of course, in degree, has been my observation 
of beer-drinking everywhere. It is peculiarly deceptive 
at first, and it is thoroughly destructive at the last." 

Various kinds of domestic drinks are sometimes pre- 
pared by adding yeast to sweet liquids in which roots 
or bitter herbs have been steeped. Those who make 
them are frequently not aware that they contain alco- 
hol ; but the yeast acts on the sugar of the sweet liquid, 
just as it does on the sweet grain-juice, and changes it 
to alcohol and carbonic acid gas. 

81. Distilled Liquors. — By heating a fermented 
liquid, the alcohol in it can be readily driven off in the 
form of vapor. This is condensed in a cool receiver, 
and the result is a new and stronger liquor. This pro- 
cess is called distillation. The alcohol of commerce is 
distilled mostly from whiskey. 

Beverages thus distilled from liquids which contain 
alcohol are commonly known as "spirits" and " ardent 
(burning) spirits." Brandy is distilled from wine, and 

l See Note iz, page 367. 



ORIGIN AND NATURE OF FERMENTED DRINKS 91 

rum from fermented molasses. Distilled liquors con- 
tain from forty to fifty per cent of alcohol, — the rest 
being water, flavored with various aromatics. 

When the beer, wine, or cider drinker has acquired 
such a craving for alcohol that the amount in those 
weaker drinks no longer satisfies him, he resorts to 
these stronger liquors. These are still more harmful ; 
and even if they do not bring the drinker swiftly to 
drunkenness, they so injure his body and mind that 
he never realizes the happiness, respect, and usefulness 
that he might otherwise have enjoyed. 

In place of happiness he has misery ; instead of 
respect, contempt ; and instead of usefulness, he 
becomes a burden to others. He sees, when too late, 
how different his life might have been but for his first 
glass, that led on to others and their consequences. 

A Costly Vice. — The annual report of the Commissioner of Internal 
Revenue for 1891, shows that the business of manufacturing intoxicating 
liquors has grown in the past year to a magnitude which it had never 
reached before. The spirits produced and deposited in distillery ware- 
houses during the last fiscal year amounted to about one hundred and 
sixteen million gallons, and the quantity of spirits in the distillery ware- 
houses at the end of the year was one hundred and thirteen million gal- 
lons, — the largest quantity ever known in these places. Outside of the 
warehouses there were, according to the figures of the Internal Revenue 
Bureau, about one hundred and fifty-three million gallons of spirituous 
liquor in the country. A total of two hundred and sixty-six million gal- 
lons of spirits, to be consumed chiefly by the people of the United 
States ! 

It would require a vivid imagination to conceive a tithe of the crime, 
misery, suffering, wretchedness, and death, that are included in that 
vast bulk of intoxicating liquor. It is estimated that the liquor con- 
sumed in the country costs the people one billion dollars a year. 



92 YOUNG FOLKS' PHYSIOLOGY 

CHAPTER VII 

DIGESTION 

82. General Plan of Digestion. — Food cannot serve 
the needs of the body until it has been converted into 
blood. In order to become blood, food must first be 
dissolved. This is done in the alimentary canal. This 
canal is a long tube, which runs through the body from 
the lips to the lower end of the spine. 

Beginning at the mouth, this canal, continued as the 
gullet, passes down through an opening in the dia- 
phragm, which forms the partition between the chest 
and abdomen. Below this it swells out into a large 
bag called the stomach. It then narrows again into 
the small intestine, which lies coiled upon itself in the 
cavity of the abdomen. It then swells out again into 
the large intestine, from which are discharged the use- 
less parts of the food, together with certain other 
waste products. 

This long digestive tube is lined throughout by 
a soft, moist, reddish kind of very thin skin, called 
mucous membrane. Layers of muscles surround the 
tube, which strengthen it, and help push along the 
food. In and around this tube are hollow organs, 
called glands. 1 They pour out certain fluids, which 

1 Glands are curious organs, of various shapes and sizes, whose special work 
it is to take out of the blood something to be used again, or to rid the blood 
of something to be cast out of the body. Thus the salivary glands make saliva, 
or spittle, and the sweat glands make sweat. The liver, which weighs about 
five pounds, is a single gland, and secretes bile ; while the glands in the intes- 
tines are so very small that they cannot be seen by the naked eye. 



DIGESTION 93 

alter the food chemically, and so fit it for absorption 
into the blood. 




Fig. 35.— Blackboard Diagram of the Digestive Canal. 

The process by which the food is made fit to mix 
with the blood is called digestion. 

83. What takes Place in the Mouth. Chewing of 



94 



YOUNG FOLKS PHYSIOLOGY 



the Food. — The mouth is a hollow box, with a movable 
floor formed by the tongue and lower jaw. At the top 
is the hard palate ; in front, the lips and the teeth ; 
and at the sides, the cheeks and the teeth. The mo- 
ment food is taken into the mouth, it is rolled over by 
the tongue, and crushed and ground into very small 
pieces by the teeth. 

This process is called chewing, or mastication. 

84. The Teeth. — The teeth are small, hard, white, 
bone-like bodies fixed in the jaws, pressing against each 



mm am "mr ^j . ipg/ ■#©£' ■■■tt^S *^JB 



f 6 



I «ff 'f|l M 



Fig. 36. — The Adult Teeth. — i, 2, The cutting teeth (incisors), 
(cuspid). 4, 5, Small grinders (bicuspids). 6, 7, 8, Griuders (molars)-. 



3, Canine 



other as the jaws work, so as to cut and grind the food. 
They are fastened into the jaws by roots, which sink 
into the bony sockets somewhat in the same way as a 
nail is held in a piece of wood. 

Teeth are made of three things, — dentine, cement, and 
enamel. Dentine, the familiar ivory of commerce, is a 



DIGESTION 



95 



bone-like substance, which forms the inside and body of 
the tooth. Outside of this dentine is a layer of cem- 
ent ; but, when the tooth appears above the jaw, the 
enamel takes its place. It is a hard, shining kind of 
polish, looks like ivory, and gives a strong protection 
for the exposed part of the tooth, called the " crown." 
Inside of each tooth is a space which holds a. delicate 
substance called the pulp, well supplied with nerves 
and blood-vessels, which enter at the root of the tooth. 




Fig. 37. — Diagram showing the apposition of the teeth. 

A child when born has no teeth : afterwards, how- 
ever, it has two sets. The first set, or milk-teeth, 
twenty in number, are shed in childhood. The second 
set, or permanent teeth, thirty-two in number, gradu- 
ally take their place. The teeth are arranged in the 
same way, and number the same, in each jaw, and in 
each half of each jaw. 



96 



YOUNG FOLKS' PHYSIOLOGY 



Thus, beginning at the centre of the* jaw, there are 
eight incisors, or cutting-teeth, or two on each side. 
They have sharp, chisel-like, cutting-edges, which cut 
up the food. These teeth are largely developed in 
gnawing-animals, such as rabbits, 
squirrels, rats, and the beaver. 
,.,„„, Then come the canine, or dog-teeth, 
two in each jaw, so called because 
they are strongly developed in 
dogs, cats, tigers, and other flesh- 




ech 



eating animals. 



Next in order come the two- 
pointed teeth, called the bicuspids, 
four in each jaw. They are so 
called because they have two points 
or cusps, for grinding the food. 
r«*s After these come the largest and 
strongest teeth in the head, which 
do the hardest work. They are 
called molars, or " grinders." 
There are six of them in each jaw. 
They have broad crowns, with four 
or five cusps or ridges for grinding. 
The last molars are commonly called the "wisdom- 
teeth ; " because they do not usually appear before the 
age of twenty, or the "age of wisdom." 

85. Mixing the Food with Saliva. — While the food 
is being chewed, it is moistened by a liquid called the 
saliva, or spittle, which flows into the mouth from 
six little glands. They are known as the salivary 
glands. There are three of them on each side, in 



Fig. 38. — Vertical Section of a 
Bicuspid Tooth (magnified). 



DIGESTION 



97 



the following positions : The parotid gland, below and in 
front of each ear; 1 the submaxillary, under the lower 
jaw ; and the sublingual, under the tongue, in the 
floor of the mouth. Each gland opens into the mouth 
by a little duct. They have a certain resemblance to a 
bunch of grapes, with a tube for a stalk. 




Fig. 39. — Salivary glands, with their ducts, on the right side. 

Saliva is rapidly poured into the mouth while the 
grinding of food is going on. Three or four pints of saliva 

1 This gland, especially in childhood, sometimes becomes inflamed and swollen. 
This disease is familiarly known as the " mumps." 



98 YOUNG FOLKS' PHYSIOLOGY 

are secreted daily. Sometimes these glands are bus- 
ily at work, even before we actually taste food. Touch 
the tongue with the finger, and the saliva will flow : it 
also pours into the mouth, even at the sight, smell, or 
thought of food. This is what is commonly called 
"making the mouth water." 

What is meant by Secretion. — It is necessary to explain at this 
point the exact meaning of secretion and excretion. The word 
Secretion comes from a Latin word which means to " sift or sepa- 
rate : " excretion comes from the Latin, and means " to sift out from." 
Both words are used to express the sifting of some substance from the 
blood. 

A secretion is something taken from the blood to be used again in the 
body for some special purpose ; while an excretion is waste matter, and 
is thrown out of the body entirely. Thus, the salivary glands secrete 
the saliva, and the liver secretes the bile. Sweat is an excretion, thrown 
off from the body by the sweat-glands. 

Those parts of the body which are engaged in secretion and excretion 
are called glands. There are a great number of glands in the body, 
varying in size, from the liver, which weighs about five pounds, to the 
small glands in the intestines, which are invisible to the naked eye. All 
glands, from the simplest to the most complex, have the same foundation 
structure. They are built, so to speak, of identical material. They con- 
sist essentially of a fine skin, or membrane, which is covered on one side 
with a layer of exceedingly minute bags called epithelial cells ; while it 
rests upon capillaries on the other side. These cells have the power of 
drawing the peculiar secretion of the gland out of the blood that is cir- 
culating through the capillaries. The moist, tender skin, or lining, on 
the inside of our lips, is a familiar example of this secreting-membrane. 

A gland may be merely a pouch in the basement membrane ; or the 
membrane may be elaborately twisted, branched, made up like bunches 
of grapes, and so on, into all kinds of complex glands. Why and 
how the cells in the liver make bile, and not gastric juice; those in the 
stomach make gastric juice, and not sweat; those in the skin make 
sweat, and not saliva; and so on, — we do not know, and we can hardly 
imagine. 

Excretion will be described in full in chapter xiii. 



DIGESTION 99 

The saliva not only softens and mixes with the food, 
and keeps the mouth moist, but it also has the power 
of acting upon all starchy matters in the food, and 
changing them into sugar. These starchy matters, as 
we have seen, before they are mixed with saliva, are 
insoluble f but, when changed into sugar, they are 
quickly dissolved in the stomach, and taken up by the 
blood. 1 

86. How Food is swallowed. — The food is now ready 
to be swallowed. The soft, moist mass is carried back- 
wards by the tongue and the muscles of the mouth into 
the funnel-shaped top of the gullet, called the pharynx. 
The soft palate pushes up and backwards, so as to pre- 
vent the food from passing into the nose. 2 

Now, besides the opening from the pharynx into the 
stomach, there is also one into the windpipe. To 
prevent the food from getting into this opening, and 
choking us, the top of the windpipe is protected by a 
little lid, a kind of trap-door, called the epiglottis. 

When we swallow, the tongue, raised and pushed 
backwards, shuts this little lid ; and thus a bridge is 



1 We can easily prove that the saliva changes starch into sugar : hold some 
boiled starch — or a little arrowroot, which is almost pure starch — in the mouth 
for a few minutes. We find that it gradually loses its thick, pasty, nature, and 
becomes thin and watery, while at the same time it acquires a sweet taste. The 
fact is, the saliva has acted on the starch, and changed it into sugar in order to 
make it soluble. This shows the necessity of properly chewing our food. If we 
bolt our food without sufficiently chewing it, the saliva does not act properly upon 
it, and a great amount of extra work is thrown on the intestines. 

2 During and after a severe attack of diphtheria, scarlet-fever, etc., in which 
diseases the parts of the throat are apt to be partially paralyzed, the soft palate 
is not able to shut off this passage into the nose : as a result, milk and other food 
often come up through the nose. 



oo 



YOUNG FOLKS PHYSIOLOGY 



made, over which the food passes downwards into and 
through the gullet, and thence into the stomach. Some- 
times, however, a morsel of food "goes the wrong 
way," — that is, is drawn into the opening of the wind- 



UVULA 




Fig. 40. — Section showing Passages to the Gullet aDd Windpipe. 

pipe, or down into the air-tubes, — and then violent 
coughing follows : by this means it may be brought up 
again. If the substance is hard and large, like a boot- 
button, orange-seed, or peanut, a person, especially a 
child, may be choked to death. 



DIGESTION IOI 

The gullet, or food-pipe, is a tube about nine inches 
long, hanging loosely behind the windpipe. Its thick 
walls are provided with hoop-like muscles, which con- 
tract with a worm-like motion, well seen when a horse is 
drinking water, and so push the food along towards the 
stomach. The pellet of food is passed along from 
above downwards by these muscles 1 in some such way 
as we would push a ring along inside of a rubber tube. 

87. Digestion in the Stomach. — The food, a moist- 
ened, partly-digested mass, has now reached the stom- 
ach. 

The stomach is a pear- 
shaped bag, or pouch, 
capable of holding 
about two quarts of 
liquid. When full, it 
is some twelve inches 

BILE_ 

long, and four inches 0UCT ( 
broad. It is placed 
across the upper part 
of the abdomen, direct- 

. Fig. 41. — Section of Stomach. 

ly under the diaphragm, 

the larger end to the left side. 

1 It is important to remember, that, in swallowing, the food and drink do not 
simply fall down the gullet. Their passage is controlled by the muscles in such 
a way that they grip successive portions swallowed, and pass them along. Even 
in swallowing a pill, there is the same process. The smaller the pill, the greater 
the difficulty in swallowing ; because the muscles have more trouble to get the 
necessary grasp on it. Some of us have seen an acrobat or juggler stand on his 
head, and drink a glass of water, and even eat in this position. We see the same 
thing every day when we notice a horse or cow drinking f;ora a pail of water on 
the ground. 

When the food is pressed backwards by the tongue into the top of the gullet, 
it is no longer under the control of the will : it is impossible to recall the mass, 
and it is necessarily carried into the stomach. 




102 YOUNG FOLKS PHYSIOLOGY 

The stomach has two openings. The opening, or 
ring, through which the food enters, and where the 
gullet ends, is called the cardiac orifice. The other, at 
the right end, where the intestines begin, and that by 
which food leaves the stomach, is called the pylorus, or 
gate-keeper. 

The walls of the stomach consist of three coats : 
(i) A tough outer coat of fibrous tissue, which protects 
and strengthens the organ ; (2) a coat of smooth, or 
involuntary, muscular fibre, which rolls the food about 
in the process of digestion, with that worm-like motion 
which we noticed in describing the gullet ; (3) a third 
or inner coat, in which the blood-vessels and nerves are 
spread out. 

This inner or mucous coat is next to the food, and 
has its surface honeycombed with millions of little pits. 
We have all seen this in tripe. In the floor of each of 
these tiny pits a number of tubes open. These tubes, 
during the process of digestion, are constantly pouring 
into the stomach a peculiar fluid, called the gastric juice. 

The gastric juice is a clear, almost colorless, fluid, with 
a sharp acid taste. It contains a peculiar substance 
called pepsin, and an acid, both of which are necessary 
to the digestion of food in the stomach. The amount 
of gastric juice has been variously estimated, — all the 
way from five to fourteen pounds daily. There is com- 
paratively little in the stomach at any one time. There 
is no loss, for it is rapidly re-absorbed by the blood. 

Now, the moment the food reaches the stomach, the 
gastric juice begins to flow, the muscles begin to con- 
tract, and the whole organ takes on a churning motion. 



DIGESTION IO3 

The food is rolled over and over, and thoroughly mixed 
with the gastric juice. Two rings, one at the entrance 
and the other at the outlet, keep the food in the stom- 
ach while it is being churned about and digested. 

The gastric juice has scarcely any effect on the 
starchy matters, but acts on the albumens, such as are 
contained in meat, cheese, eggs, etc., to make a com- 
plete solution. 




Fig. 42. — The Stomach, showing its outer layers of muscular fibres. 

Some of these dissolved albumens, together with some 
of the starchy matters dissolved by the saliva, are at 
once sucked into the blood by the blood-vessels in the 
walls of the stomach. The remainder of the mass, a 
thick, pulpy, soup-like substance, resembling gruel, is 



104 YOUNG FOLKS PHYSIOLOGY 

called chyme, meaning juice, with an acid odor and 

taste. 

Chyme contains more or less albuminoid matters, 
together with the starchy elements which have not been 
changed into sugar, and all the fat. The fat may be 
seen floating in large drops on the surface of the chyme. 
The ring at the outlet, or pylorus, now relaxes ; and the 
partially digested food is forced in little jets into the 
duodenum, or first part of the small intestines. 

88. Digestion in the Intestines. — The intestines con- 
sist of a long tube, or canal, which fills the greater part 
of the abdomen. They are divided into the small intes- 
tines, about twenty-five or thirty feet long, and the large 
intestines, five or six feet in length. To get all this 
into the small space it has to occupy, it is doubled upon 
itself many times. The first portion of the small intes- 
tines, 1 which is directly continued from the stomach, is 
called the duodenum, because its length is about equal 
to the breadth of twelve fingers. 

Let us now see what goes on in the duodenum. Two 
pipes, or ducts, unite, and enter it. .One comes from 
the gall-bladder, and brings the bile ; the other from the 
pancreas, and brings the pancreatic juice. These two 
tubes unite, and enter the duodenum at the same 
place. 

The liver is the large reddish-brown organ situated 
just under the diaphragm, and on the right and upper 
side of the abdomen. It is the largest organ in the 
body, and weighs about fifty ounces. The liver secretes 

1 The small intestine includes three parts, — duodenum, jejunum, and ileum. 
The large intestine includes the colon, ccecum, and rectum. 



DIGESTION I05 

from the blood a greenish fluid called the bile. It is 
stored up in a kind of little pear-shaped bag attached to 
the liver itself, and called the gall-bladder. 

The bile is a thin, greenish-yellow, bitter fluid. Some- 
times it is olive-brown in color ; but, when acted upon 
by the gastric juice, it takes on a distinctly yellow 
or greenish hue ; hence the appearance of vomited 
bile. 

The chief use of the bile is to digest the fatty parts 
of the food, upon which the gastric juice does not act. 
The bile also aids in separating the nutritious from the 
useless parts of the food. 1 

The pancreatic juice is very much like saliva. It is 
secreted by a long, narrow, flattened gland called the 
pancreas, or sweet-bread, which lies deep in the cavity 
of the abdomen, just behind the stomach. It is often 
said to resemble a dog's tongue in shape. 

The pancreatic juice finishes the work which the 
saliva began. It acts chiefly upon the starchy matters 
of the food which have escaped the saliva, and changes 
them into sugar. At the same time, however, it follows 
up the work of the gastric juice, and dissolves any albu- 
mens which have not been dissolved in the stomach. 

The inner surface of the intestines also pours in a 
liquid called the intestinal juice; which, like the saliva, 

1 The bile is alkaline ; its chief ingredients are two salts of soda. We have 
tried, perhaps, to clean a bottle which has held oil. We put in some soda and 
warm water, and then shake the bottle.. The soda breaks up the oil into tiny 
drops, which float round the creamy mixture. This is exactly what the bile does 
with the fatty parts of the food. In other words, it makes an " emulsion." Cod- 
liver oil is often mixed with other things to disguise the fishy taste. This creamy 
mixture, known as an " emulsion of cod-liver oil," is a familiar sight in the drug- 
stores. 



106 YOUNG FOLKS' PHYSIOLOGY 

acts upon the starchy matters. At the same time, how- 
ever, this juice acts as a solvent on any albuminoid 
matters or fats still undissolved. In fact, this intestinal 
juice has the properties of saliva, gastric juice, bile, and 
pancreatic juice, all in one. 

Like a prudent housekeeper, Nature intends that this 
last digestive fluid in the digestive tube shall act upon 
all matters in the intestines still left undissolved by the 
other juices, so that no part of the food may be wasted. 
The chyme thus acted upon by these different fluids 
has the appearance of a thick cream, and is called 
chyle. 

The muscles of the intestines, like those of the 
stomach, are almost continually at work. The whole 
intestinal tube is constantly moving in a manner some- 
what resembling the motions of a worm ; and, all this 
time, it is squeezing and forcing forward its contents. 
In this way, a portion of the food is acted upon by 
the several parts of the intestinal canal. 

89. Absorption. How the Blood feeds on the Food. 
■ — The soup-like mass which left the stomach under the 
name of chyme, has now been changed into a thick 
cream called chyle. Squeezed slowly along the intes- 
tines by the worm-like twistings of the muscular walls, 
most of the nutritious parts of this milky fluid is sucked 
up drop by drop by the lacteals, and poured into the 
current of the blood. The process by which the di- 
gested materials are taken into the blood is called absorp- 
tion. 

This is done chiefly by two sets of vessels, — first, by 
the lacteals, or lymphatics ; second, by the blood-vessels. 



DIGESTION 



I07 



go. Absorption by the Lacteals and Lymphatics. — 

The inner surface of the intestines is not smooth and 
shiny, like the outside, but shaggy, or, rather, has a vel- 
vety appearance. This is because the inner lining is 
crowded all over with millions of little tags, like very 
small tongues, hanging down into the inside of the 
intestines. These hair-like projections are called villi, 
meaning " tufts of hair." They are tiny affairs, about 
one-thirtieth of an inch long; and a five-cent piece 
would cover five hundred of them. These give the 
appearance of the pile „^ ial 
on velvet. We are, of 
course, familiar with 
this appearance in tripe. 

In each one of these 
villi is a network of the 
finest blood-vessels, and 
a tube, or canal, called a 
lacteal, so called from 
a Latin word meaning 
"milky," and because fig. 43.— Two van (magnified), 

it carries a white, milky fluid. Millions of these lacteals 
dip down into the intestines, like little ropt-fibres, 
and suck up from its creamy contents the fatty matters 
of the chyle. 

The lacteals, after passing through a number of 
glands — like way-stations on a railroad — in the abdo- 
men, unite into larger tubes, and finally open into a 
little sac, or bag, in the loins, called the receptacle of 
the chyle. 

Leading upward from this is a tube called the thoracic 




io8 



YOUNG FOLKS PHYSIOLOGY 



dnct, which carries the fluid upwards, along the back- 
bone, and pours it into a vein in the neck. The tho- 
racic duct is about eighteen inches long, and about as 
large as a goose-quill. It acts as a feeding-pipe, to 
empty the nutritive matter absorbed from the food into 




Fig. 44. — Lacteals ending in Thoracic Duct, which empties into a Vein in the Neck. 

the blood-current. The lacteals are merely lymphatics, 
which begin in the villi of the intestines. 

In all parts of the body, except the brain, spinal cord, 
eyeball, and tendons, we find thin-walled vessels busily 



DIGESTION < IO9 

at work taking up, and making over anew, waste fluids 
or surplus materials derived from the blood and tissues 
generally. They seem to start out of the part in 
which they are found, like the rootlets of a plant in the 
soil. The tiny roots join together, and make larger 
roots. They carry a colorless fluid called lymph, very 
much like blood without the red corpuscles. The tubes 
in which this fluid flows are called lymphatics. 

These tubes have rounded bodies at many points of 
their course, scattered like depots along a line of 
railroad, called lymphatic glands : They seem to be fac- 
tories to make over the lymph in some way, and to fit it 
for renewing the blood. Most of the lymphatics at last 
unite with the lacteals, and empty their contents into 
the thoracic duct. 

Thus, again, Nature, like a careful housekeeper, 
uses up even the waste matters of our bodies, in 
providing them with nourishment. 

91. Absorption by the Blood-vessels. — Soluble sub- 
stances can pass through the delicate walls of the blood- 
vessels. The inner lining of the digestive canal, es- 
pecially the small intestines, is rich in blood-vessels. 

The Spleen. — The spleen is a reddish, soft, and pulpy organ. It is 
about five inches in its longest diameter, and an inch thick, and situated 
near the left end of the stomach, just under the ninth, tenth, and eleventh 
ribs. The use of this organ is not known. It has probably something 
to do with the formation of blood-corpuscles. In certain diseases, like 
malarial fever, it may reach an enormous size. Two other glands, the 
thymus and thyroid glands, known when taken from the lower animals 
as the " breast sweet-bread " and " throat sweet-bread," are situated in 
the neck. They are regarded as appendages of the lymphatic system. 
Their use is not known. 



I 10 YOUNG FOLKS PHYSIOLOGY 

Hence those parts of the food which have been made 
liquid, and capable of forming a soluble mixture with 
the blood, are absorbed directly by the small veins and 
capillaries ; although a small part finds its way into the 
lacteals. 

The emulsified fats, as we have seen, are mostly taken 
up by the lacteals. Certain materials, dissolved by the 
gastric juice and ingested liquids, are taken up directly 
by the blood-vessels of the stomach. An enormous 
absorbing surface is provided in the small intestines, 
by the arrangement of the mucous membrane in folds, 
and by the countless numbers of villi, which are con- 
stantly absorbing nutritive materials through the myri- 
ads of their tiny blood-vessels. 

It is important to remember that all the blood cir- 
culating in the digestive organs, and taking up the 
soluble nutritive matters, must pass through the liver 
before entering the general circulation ; and from it the 
liver selects and elaborates its secretion. 

92. The large Intestines. — The large intestines begin 
at the lower extremity of the small intestines, and 
consist of three parts, the ascending, the transverse, 
and the descending colon ; the last of these being con- 
tinued into the rectum. This digestive tube, which is 
about six feet long, first passes up the right side of the 
abdomen, then across under the liver and stomach, and, 
lastly, descends on the left side of the abdomen to the 
rectum. 

As the food-mass passes along into the large intestines 
almost everything which is fit to be taken up has been 
absorbed. Some digestion may go on in them, but it 



DIGESTION III 

is of little account. They are really a kind of passage- 
way, or temporary storehouse, for undigested and waste 
matter, which should be cast out of the body as 
speedily as possible. 

93. How much to Eat. — The quantity of food 
needed to keep the body in good health varies very much 
according to circumstances. The general principles are 
these : Action is the law of every living being. Waste 
attends action : hence, in the main, the supply of food 
must equal the waste of the body. The greater the 
amount of exercise, the more food is called for to supply 
the waste. During the time of growth, a still greater 
quantity is needed to build up new tissues ; hence 
growing children generally have a good appetite and 
a vigorous digestion. The same holds good of persons 
getting well of some long and wasting sickness. 

The quantity required also depends very much upon 
one's business. Those who work hard and long, either 
with the body or mind, as teamsters, blacksmiths, farm- 
ers, doctors, and editors, need a goodly amount of 
nutritious food. Those who work in-doors, as clerks, 
milliners, students, and book-keepers, can get along 
with a smaller quantity. In cold weather, or in cold 
climates, a greater quantity of " fuel-food" is necessary 
than in warm weather or in a tropical climate. 1 

1 " Travelers' accounts of the amount of food consumed by the natives of the 
frigid zone are almost incredible. 

" Dr. Hayes, the Arctic explorer, states from his own observation, that the 
daily ration of the Esquimos is from 'twelve to fifteen pounds of meat, about one 
third of which is fat. He once saw an Esquimo consume ten pounds of walrus 
flesh and blubber at a single meal, which however lasted several hours, with the 
thermometer 6o° or 70° below zero. Some members of his own party manifested 
a constant craving for fatty substances, and were in the habit of drinking the 
contents of the oil-kettle with evident relish." — Flinfs Physiology. 



112 YOUNG FOLKS PHYSIOLOGY 

An appetite for plain, simple, well-cooked food is a safe 
guide to follow. Every person in good health and with 
moderate exercise should eat well : he should have a 
keen appetite for his food, and enjoy it. Young, grow- 
ing, and vigorous persons should eat until appetite is 
fully satisfied, provided they have enough of exercise, 
both mental and bodily. 

It is easy to know when we are eating too much. An 
overworked stomach makes its condition known by a 
sense of fulness, uneasiness, drowsiness after meals, 
and sometimes a real distress. If we keep on eating 
too much and too rich food, the complexion is apt to be 
muddy, the face more or less covered with blotches and 
pimples, the breath has an unpleasant odor, and the 
general look of the face is dull and unwholesome. 

g4- What to Eat. — Food should be both nutritious 
and digestible. It is nutritious in proportion to its 
capacity to furnish suitable substances to be taken into 
the blood. Foods are digestible just as they are acted 
upon by the digestive fluids. Certain foods, as the 
vegetable albumens, are both nutritious and digestible. 
A man will grow strong and keep healthy on any of 
them. 1 

1 The splendid races of Northern India live on barley, wheat, millet, and rice, 
as their staple food. In Southern India, millions of people live on pease and 
rice. 

There have been many generations of the hardiest men in the world in the 
north of England and Scotland, who lived on oat-meal and milk. These men 
literally lived their lifetime without taking any other food except green fruits, 
vegetables, and the cereals. 

The Roman gladiator's chief article of diet was barley ; and the ancient sol- 
dier endured his long marches and severe fighting on the cereals boiled in water, 
when meat could not be had. 



DIGESTION 113 

We can safely eat some animal food every day, yet 
it is well to remember that the vegetable albumens 
supply all that is needed for the nourishment of the 
body. A strong, hearty person may eat half a pound or 
so of meat daily ; yet he should take other foods, such 
as bread, oatmeal, beans, rice, and milk. These foods 
are all good, all cheap, all digestible, and all palatable. 

Vegetable foods are less stimulating than animal. 
Hence they are more suitable for children. Beef, pork, 
ham, oysters, and rich pastry should be sparingly given 
to children. The plainest and simplest diet is the best. 
It is much better for a child to go to bed on a supper of 
oatmeal, baked apples, or mush and milk, than warm 
bread, cake, pie, and fried meat. Parents cannot look too 
sharply after the food they give their children. This is 
especially important at the present day, when all kinds 
of strange devices are resorted to, to furnish the public 
with fanciful and tempting foods. 

Students must also look sharp to their diet. It is 
much better for them to begin a day's study with a 
breakfast of oatmeal, stale bread, a soft-boiled egg, and 
a glass of milk, than strong coffee, sausage, and hot 
biscuit. 

95. When to Eat. — Three meals a day, from five to 
six hours apart, should be eaten. These should be 
arranged mainly according to one's occupation. The 
stomach, like other organs, does its work best when its 
tasks are done at regular periods. Hence, regularity 
in eating is of the utmost importance. 

Eating out of meal-times should be strictly avoided, 
for it robs the stomach of its needed rest. Food, 



114 YOUNG FOLKS PHYSIOLOGY 

eaten when the body and mind are tired, is not well 
digested. Rest, even for a few minutes, should be 
taken before eating a full meal. It is a good plan to 
lie down, or sit quietly and read, fifteen minutes before 
eating. 

Severe exercise and hard study just after a full meal, 
are very apt to check digestion. The reason is plain : 
after a full meal, the vital forces of the body are called 
upon to help the stomach digest its food. If they are 
forced, in addition to this, to help the muscles or brain, 
digestion will be hindered, and a feeling of dulness and 
heaviness follows. This, in time, often results in the 
common form of ill digestion called "dyspepsia." 

We should not eat for at least three hours before 
going to bed. When we are asleep, all the vital forces are 
at a low ebb, and digestion is difficult, if not impossible. 

We should make it a point not to omit a meal unless 
forced to do so. Children, and even grown-up people, 
often have the bad habit of going to school or to work 
in a hurry, without eating any breakfast. There is sure 
to be an "all-gone" feeling at the stomach before 
another meal-time. 

The state of the mind has a great deal to do with 
digestion. Sudden fear or joy, or unexpected news, 
may take away the appetite at once. Hence, so far as 
we can, we should laugh and talk at our meals, and 
drive away all anxious thoughts and unpleasant topics 
of discussion. If hunger is a good sauce, so also is a 
jolly laugh. 

96. How to Eat. — Eat slowly, and thoroughly chew 
the food. Do not take too much drink with the food. 



DIGESTION 115 

Our teeth were made to chew our food, and the saliva 
to moisten it, and help along digestion. If the food is 
well chewed, the saliva and the gastric juice act more 
readily. It is not only bad manners to eat rapidly, but 
it is a violation of the simplest law of digestion. 

If we take too much drink with our meals, the flow 
of the saliva is checked, and digestion is thus hindered. 
Rapid eating, with a great deal of drink to wash down 
the food, is almost sure to result in dyspepsia. 

Do not take the food and drink too hot or too cold. 
Such substances as very hot bread and coffee often 
injure the enamel of the teeth, and are slowly digested 
in the stomach. If the food and drink are taken too 
cold, undue heat is taken from the stomach, and diges- 

Proper Care of the Bowels. — Irregularity in eating, too much 
finely-bolted flour, and not enough fruit and vegetables, rich pastry, 
negligence or carelessness in attending to a regular daily evacuation of 
the bowels, lead to the very common and distressing trouble known as 
constipation, or costiveness. As we grow older, this trouble generally 
grows worse. Many persons resort to all kinds of patent pills and 
medicines, which, for the most part, act only for the time, and do 
not remove the cause of the ailment. Such remedies do a deal of 
harm after a time, and are almost sure to leave the bowels in a worse 
condition. 

We must pay strict attention to the proper action of the bowels. The 
formation of a regular habit is of the utmost importance. The bowels 
can be trained to act at a certain time every day. Take great pains to 
eat coarse food, such as oatmeal, corn-bread, vegetables, stewed prunes, 
dates, figs, etc. Drink a glass of water just after getting out of bed in 
the morning. Rochelle or Seidlitz powders maybe needed at times; 
they are safe, and will do no harm. Vigorous muscular exercise, espe- 
cially kneading the muscles of the abdomen, is a valuable help. 

If these things do no good, consult a physician before purgative medi- 
cines are used in a hap-hazard sort of way, simply because some friend 
urges their use. 



1 16 YOUNG FOLKS' PHYSIOLOGY 

tion delayed. The natural temperature is about ioo° 
F. If we drink freely of ice-water or cold well-water, 
its temperature will fall about 30 ; and it will take half 
an hour or more for the stomach to regain its natural 
heat. 

Drinking freely of very cold water when the body is 
heated is a dangerous practice, and, aside from its ill 
effects on digestion, has occasionally resulted fatally. It 
is a poor plan to bolster a flagging appetite with highly- 
spiced food and bitter drinks. An undue amount 
of pepper, mustard, horse-radish, pickles, fancy meat- 
dressings, and highly-seasoned sauces, may stimulate 
digestion for the time, but, used in excess, they soon 
weaken it. 

97. The Proper Cooking of Food. — To prepare, cook, 
and serve food well, is a fine art. To voluntarily leave 
this important work to raw and untrained servants, is 
an evidence of false notions, and of a neglected or one- 
sided education. 

A knowledge of the principles and practice of cook- 
ing should form a part of every young person's educa- 
tion. Many an unhappy home is due to the neglect of 
the orderly and cleanly housekeeping and good cooking 
that raises the housekeeper to the dignity of the home- 
maker. Many a man has been led into taking alcoholic 
drinks to quiet a craving caused by his system being 
imperfectly nourished. He is really hungry, not be- 
cause of any lack in the quantity of his food, but 
because of its poor quality. 

Many a constitution that might otherwise have been 
sufficiently strong and healthful to meet the demands 



DIGESTION 117 

of life, has been ruined ; and dyspepsia and other forms 
of indigestion have resulted from the use of fatty, fried, 
soggy, heavy, and otherwise unwholesome food due to 
poor cooking. 

Every young woman who goes into a home of her 
own, from the office, shop, factory, or any position or 
occupation where she has had little or no practice in 
cleanly, orderly housekeeping, including good cooking, 
should take a special course of instruction in these mat- 
ters so important to the health and welfare of a house- 
hold. 

98. Care of the Teeth. — The care of the teeth is an 
important matter. It is our duty to take the very best 
care of them, and to keep them as long as possible. 
Teeth are prone to decay. We may inherit poor and 
soft teeth : our ways of living may make bad teeth 
worse. 

If an ounce of prevention is ever worth a pound of 
cure, it is in keeping the teeth in good order. They 
should be thoroughly cleansed night and morning with 
a soft brush and warm water. Castile soap, and some 
simple tooth-powder with no grit in it, may be occasion, 
ally used. Dentists say that we should always cleanse 
the teeth before going to bed. The brush should be 
used on the inner or back side of the teeth, as well as 
on the front side. 

The enamel once broken or destroyed is never re- 
newed. The tooth is left to decay, slowly but surely : 
hence we must be on our guard against certain things 
which may injure the enamel. Picking the teeth with 
pins and needles is hurtful. We should never crack 



Il8 YOUNG FOLKS' PHYSIOLOGY 

nuts, crush hard candy, or bite off stout thread with the 
teeth. Metallic tooth-brushes, gritty and cheap tooth- 
powders, and hot food and drink, often injure the 
enamel. 

We should never use any of the tooth-powders and 
washes, especially advertised and secret preparations, 
warranted to harden the gums, and whiten the teeth. 
Dirty and decayed teeth are a frequent cause of an 
offensive breath and a foul stomach. 

We should exercise the greatest care in saving the 
teeth. The last resort of all is to lose a tooth by hav- 
ing it extracted. The skilled dentist will save almost 
anything in the form of a tooth. 

99. Effect of Alcohol on the Stomach-Digestion. — 
Alcoholic liquors act as a mild or strong irritant of the 
stomach, just as they are taken, raw or diluted. Their 
habitual use leads to most distressing forms of stomach 
disease. 1 If we could look into the stomach, as Dr. 
Beaumont looked into the stomach of Alexis St. Martin, 2 
just after taking a drink of raw spirit, we should find 
that the inner surface would be bright red when the 
alcohol touched it, and far more so than after taking 
ordinary food. Alcohol irritates the lining of the 

1 " Many cases of dyspepsia are due to alcohol, solely and wholly." — J. Mil- 

NER FOTHERGILL, M. D. 

" Nothing with such certainty impairs the appetite and the digestive power as 
the continued use of strong alcoholic liquids." — Pavy on " Food.' 1 '' 

2 The process of gastric digestion was studied many years ago by Dr. Beau- 
mont and others, in the remarkable case of Alexis St. Martin, a French-Canadian, 
who met with a gun-shot wound which left a permanent opening into his stomach, 
guarded by a little valve of mucous membrane. Through this opening the lining 
of the stomach could be seen, the temperature ascertained, and numerous experi 
ments made as to the digestibility of various kinds of food. 






DIGESTION 119 

stomach, and dilates the tiny blood-vessels, just as 
brandy dropped into the eye would make it look red and 
watery. 

Alcohol, like any other irritant, also causes the gastric 
juice to flow, just as the eye, when injured, becomes 
flooded with tears. The power of the gastric juice 
to dissolve food is at the same time either greatly 
diminished or entirely destroyed. For, whenever alcohol 
comes in contact with gastric juice, the pepsin, without 
which it cannot digest food, is precipitated. This 
hinders digestion until the alcohol is sufficiently diluted 
with water drawn from the stomach to prevent further 
precipitation of the pepsin. 1 Thus an extra amount of 
useless work is thrown upon the glands and makes them^ 
less active. 

If this unnatural excitement of the glands of the 
stomach is kept up for some time, they become weak- 
ened, and the gastric juice is diminished in quantity 
and made poorer in quality. The result is alcoholic 
dyspepsia. 

It has even been found by drawing off the contents 
of the stomach with a siphon, during various stages 
of digestion when alcohol has been taken, that it 
entirely suspends the transformation of food while 
it remains in the stomach, and that only after the 
alcohol leaves the stomach does digestion go on at a 
fair rate. 

In the case of St. Martin it was observed by 
looking directly into his stomach that when a whole- 
some dinner was digesting in good order, a glass of 
gin arrested the process, which was not continued 

1 See Note 12, page 368. 



120 YOUNG FOLKS PHYSIOLOGY 

until after the alcohol had passed out of the 
stomach. 

Now, when this alcoholic irritant is poured into the 
stomach for days, weeks, and even for years, it is no 
wonder that the stomach becomes altered in its struc- 
ture. 1 There is a chronic inflammation of the inner 
coats : the walls of the stomach become thicker and 
harder, and traces of ulcerations are often found. Be- 
cause the stomach is unable to digest food properly, 
many other organs of the body suffer as a result. 

ioo. Effect of Alcohol on the Liver. — The liver is pe- 
culiarly liable to diseases due to alcoholic liquors. 2 When 
alcohol is taken up by the blood-vessels of the stomach, 
.it is carried directly to the liver, and filtered through 
this great organ before it reaches the heart. This, as 
we have been told, is a part of the portal circulation. 
Hence the poisonous effects of alcohol are strongly 
marked in the liver, especially among hard drinkers, 
and in hot climates. 

The blood-vessels of the liver are overworked, and 
the capillaries engorged with blood. This causes, first, 

1 " The structural alterations induced by the habitual use of alcohol, and the 
action of this agent on the pepsin, seriously impair the digestive power. Hence 
it is, that those who are habitual consumers of alcoholic fluids, suffer from dis- 
orders of digestion. Heartburn, water-brash, acid stomach, and a peculiar retching 
in the morning, are produced." — Robert Bartholow, M.D. 

"Alcohol in any appreciable quantity diminishes the solvent power of the 
gastric fluid so as to interfere with the process of digestion instead of aiding it.". 
— W. B. Carpenter, M.D. 

" If the amount of alcohol be increased, or the repetition become frequent, 
some part of it undergoes acid fermentation in the stomach, and acid eructations 
or vomitings occur. With these phenomena is associated catarrh of the stomach 
and liver with their characteristic symtoms — loss of appetite, feeble digestion, 
sallowness, mental depression, and headache." — Dr. James C. Wilson. 

2 See Note 13, page 369. 



DIGESTION 121 

an enlargement of the liver, and then a shrivelling of 
the substance of the organ, together with a rough and 
" bunchy " surface. This, in medical language, is called 
cirrhosis} meaning tawny, or orange-colored, but in 
common phrase it gets the name of " hob-nail " or "gin- 
drinker's" liver, from its appearance. 2 

Again, fatty decay (called fatty degeneration), due to 
alcohol, may take place in the liver : this makes the 
organ of great size, sometimes weighing from fifteen to 
twenty pounds ; and one case is related of a drunkard's 
liver that weighed fifty pounds. 

101. The Effect of Tobacco on Digestion. — The use 
of tobacco, either in smoking or chewing, causes the 
glands of the mouth to send out large amounts of saliva ; 
this, in time, weakens them and causes dryness of the 
throat. It also interferes with digestion. 3 Very fre- 
quently smoking leads to indigestion, which can only 
be cured by abandoning the tobacco. 4 

1 " Cirrhosis of the liver is notoriously frequent among drunkards, and is in 
fact almost, though not absolutely, confined to them." -Robert T. Edes, M.D. 

2 " Alcohol acts on the liver by producing enlargement of that organ, and a 
fatty deposit, or " hob-nailed " liver mentioned by the English writers." — W. B. 
Carpenter, M.D. 

8 " Tobacco impairs digestion, poisons the blood, depresses the vital powers, 
causes the limbs to tremble, and weakens and otherwise disorders the heart. 
Physicians meet with thousands of cases of dyspepsia connected with the use of 
tobacco in some one of its forms." — Dr. Mussey. 

4 See Note 14, page 371. 



122 YOUNG FOLKS PHYSIOLOGY 



CHAPTER VIII 

THE BLOOD AND ITS CIRCULATION 

102. Uses of the Blood. — Every child knows, that if 
he cuts or scratches his finger, or even pricks it with a 
pin or needle, blood flows. What is true of the finger, 
is also true of every other part of the body, except the 
hair and nails. 

The tiny blood-vessels go everywhere, through the 
muscles and nerves, over and within the brain, through 
every particle of every bone, — the blood flows every- 
where. Every little bit of bodily tissue is bathed with 
the blood. The blood makes everything common as it 
flies from spot to spot. Wherever it goes, it has some- 
thing to bring, and something to carry away. The 
blood lives on the food we eat, and the tissues live on 
the nutritive material from the blood. 

The blood, in its ceaseless round, not only brings new 
material for repair, but it is also a kind of sewer-stream 
that drains off waste matters, and carries them to 
organs whose duty it is to cast them out of the body. 

103. How Blood is made up. — Blood, as it is drawn 
from the body, is a red, somewhat sticky, fluid, thicker 
than water, and apparently all of one substance. It is 
not so simple a fluid as it looks. If we let fall a small drop 
of freshly drawn blood upon a piece of glass, and exam- 
ine it under a microscope, we shall see that this fluid is 
not all of one substance. It consists of an almost color- 




THE BLOOD AND ITS CIRCULATION 1 23 

less fluid called the plasma, and an enormous multitude 
of little bodies called corpuscles, floating in the liquid. 
These corpuscles are of two kinds, red and white. 1 

104. Blood Corpuscles. — The red color of the 
blood is due to millions of little red corpuscles which 
float about in it. When carefully 
measured they are found to be 
about the 3-^Q-Q of an inch in 
diameter. The white corpuscles 
are larger, being about the 2F00 
of an inch across. 

The red corpuscles are so closely fig. 45-— Human Biood- g iob- 

1 i,i, ., 1 ii i 11 ules ; a, seen from the surface ; 

packed, that the blood, as a whole, b> seen from the side . c> united 

looks Uniformly red. In the Same in rouleaux; d, rendered spheri- 
cal by water ; e, decolorized by 

way, a clear white glass bottle, the same; /, Biood-giobuies 
filled with red beads and water, shrunk by evaporation. 
would look uniformly red at a short distance. Imagine 
a small brook all alive with little red fishes, and it would 
give some idea how the red corpuscles make the blood 
appear red. The red corpuscles are by far the more 
numerous, there being about five hundred of them to 
one of the white corpuscles. 

In shape the red corpuscles are flattened circular 
disks, resembling somewhat pieces of coin. They have 
something of the shape of an India-rubber air-cushion 
when blown up with air. They are not hard and solid, 

1 The total quantity of bload in the body is about one-thirteenth of the weight 
of the body. Hence a man of average size has from ten to twelve pounds of 
blood. Of this amount, water makes up nearly four-fifths : only about one-fifth 
consists of dry solids. The solids consist mainly of the corpuscles, the albumen of 
the serum, and fibrine. 

The blood also contains a small quantity of minerals and salts. The most im- 
portant are iron, potash, soda, phosphorus, and sulphur. These are all essential 
to healthv blood. 



I 2 j. YOUNG FOLKS' PHYSIOLOGY 

but resemble tiny pieces of red jelly rather than any- 

In size they are so very small, that, if we had fingers 
delicate enough to handle them, we could pack away 
some fifty thousand of them on the head of a pin. It 
is said that some five million of them will float round 
in a single drop of blood. Under the microscope, the 
flat sides of these disks stick to one another in rolls, 
piled together like so many gold dollars. 



c - Z 



? mM ® • ^ ®' 




The red corpuscles absorb oxygen in the lungs, and 
cany it for distribution to the various tissues of the 
body. Night or day, whether we are asleep or awake, 
millions of these tiny oxygen-carriers are as busy as 
bees. The blood has been beautifully called "the river 
of life." 1 This is especially true of the red corpuscles. 
They may well be compared to a countless fleet of little 
boats which are constantly floating, along "-the river of 
life " in our bodies. 

i So dependent is all fife on this fluid, that should the Wood fail, for an 
instant, to reach the brain, all consdonsness would at once cease; and if for a 

it- -•;::-:- ' :t ::,t'.i -:.'.£ :t.^a 



THE BLOOD AND ITS CIRCULATION 125 

The white corpuscles are slightly larger than the red, 
and are not flattened. As we watch them by means of 
the microscope, rolling and tumbling about, we see that 
at one time they are round like a base-ball, and of such 
a size that about twenty-five hundred of them would 
just reach one inch. Shortly afterwards, however, 
they change this form, and become pear-shaped, three- 
sided, and so on, in endless variety. The function of 
the white corpuscles is not certainly known. 

105. Coagulation, or Clotting. — If a basin of fresh 
blood is allowed to stand for a short time, it will sepa- 
rate into two parts : one, a sticky, jelly-like mass, called 
the clot, settles to the bottom ; the other, a straw-col- 
ored, watery fluid, called the serum, at the top. This 
change of the blood, after it is drawn from the body, 
into a jelly-like, semi-solid mass, is called clotting, or 
coagulation, of the blood. 

The watery part, or serum as it is called, is blood 
out of which the corpuscles have been strained by the 
process of clotting. It is largely made up of water, 
with albumen dissolved in it. If we try to boil serum, 
we find we cannot do it. Before it boils, it " sets " into 
a stiff, solid mass, just like the white of a hard-boiled 
egg- 

The clot consists mainly of two substances, — the 
corpuscles, and a network of white, tough, fibrous 
threads, called fibrine. It is owing to the presence 
of fibrine that the blood clots. The corpuscles get 
snarled into the meshes of the fibrine, and thus the 
clot is formed. Fibrine may be seen by whipping 
fresh blood with twigs, to which it will stick in fine 



126 YOUNG FOLKS' PHYSIOLOGY 

threads. The same thing can be done by beating up a 
bowl of fresh blood with an egg-beater, just as eggs are 
beaten for cake. 

The power of coagulation is of the most vital impor- 
tance. When a person receives a severe wound, he 
would bleed to death unless clotting set in. Nature in 
this way plugs up the wound with clots of blood, and 
prevents excessive bleeding. 

106. General Plan of Circulation. — If all the tissues 
and organs of the body stand in such constant need of 
blood, there must needs be some special machinery to 
furnish them with this vital fluid. We shall find this 
to be the fact. Let us begin to study this apparatus. 

In the first place, there is in the chest a powerful 
forcing-pump, called the heart, from which pipes are 
distributed to all parts of the body. 

One set of pipes, called arteries, carries the blood 
from the heart. 

Another set of pipes, called veins, brings it back to 
the heart. 

The manner in which blood is made to flow through 
vessels of the body may be compared to the way in 
which water is supplied to a city. The heart is the 
pumping-engine which forces the blood into the main 
pipes for the supply of the several districts. 

And as through the city the great water-mains 
branch and sub-divide into smaller pipes for the supply 
of districts, streets, houses, and rooms, so in the body 
the blood-vessels divide over and over again, to furnish 
a supply of blood to the smallest organs and the most 
minute parts of our bodily frame. The parallel ends 



THE BLOOD AND ITS CIRCULATION 



127 



here. The water supplied to the city does not return to the 
pumping-station, whereas the blood returns to the heart. 
When the blood has been pumped through every 
part of the body, and has given to it its nutritive sup- 
ply, it receives from the tissues certain waste matters, 
the result of wear and tear. Hence the blood is no 
longer fit for nourishment. It is now more like a kind 
of sewer-stream laden with waste matters. These, in 
due time, are brought to certain organs, as the lungs, 
the skin, and the kidneys, and cast out of the body. 




Fig. 47. — The Heart and its Large Blood- Vessels. 

107. The Heart. — The heart is a hollow, muscular 
organ, somewhat like a pear in shape. It is hung 



128 



YOUNG FOLKS PHYSIOLOGY 



almost in the centre of the chest, above the diaphragm, 
partly overlapped by the lungs, and opposite the breast- 
bone. It is about the size of one's closed fist, and is 
composed of involuntary muscular fibre. 



PULMONARY 



ONARY 
EINS 




Fig. 48. — Left Section of Heart. 



The heart is of a rounded, conical shape (some com- 
pare it to the shape of a cocoanut), and placed with 
the broad part uppermost, and the point slanting down- 
wards and to the left, where it may be felt beating, 
between the fifth and sixth ribs. 

The heart is a double organ, with a partition-wall 
running down the centre from top to bottom, which 
separates the right side from the left. Each of these 
sides has two hollow chambers, or cavities, — an upper' 
one called an auricle, from its fancied resemblance to 



THE BLOOD AND ITS CIRCULATION 1 29 

an ear; the other and lower one called a ventricle. 
Hence there are two upper chambers called auricles, 
and two lower chambers called ventricles. 

The heart is a muscle : hence it can contract. When 
each of its chambers contracts, blood is forced to flow 
into the next chamber or a blood-vessel, as the case 
may be. The walls of the ventricles are stouter and 
stronger than those of the auricles, and those of the left 
ventricle are much stouter than those of the right ven- 
tricle. The right auricle opens into the right ventri- 
cle, and the left auricle into the left ventricle ; but there 
is no connection between one side of the heart and the 
other. 

108. Valves of the Heart. — The openings between 
the auricles and ventricles are guarded by little swing- 
doors, called valves. These valves may be roughly com- 
pared to folding-doors or gates, which, by opening only 
one way, allow the blood to flow in that direction, and 



Work done by the Heart. — The heart is a wonderfully busy 
machine, pumping away without getting tired, night and day for eighty 
years or more, perhaps, at the rate of seventy-two strokes every min- 
ute, over forty-three hundred times every hour, and nearly thirty-eight 
million beats every year. At each stroke, each ventricle pumps about 
six ounces, or nearly fifty teaspoonfuls, of blood. About eighteen 
pounds of blood are moved every minute, or twelve tons every day. 

It is calculated that the total amount of daily work done by the 
heart in a full-sized man is equivalent to the lifting of a ton weight to 
the height of two hundred feet. This is estimated to be about one-fifth 
of the whole amount of energy which a man puts forth in the form of 
heat and motion. While the cavities are filling with blood, and its mus- 
cles are relaxed, the heart has a brief rest : otherwise, it could not keep 
up its patient and tireless pumping of over four thousand tons of blood 
every year, from birth to death. 



-5- 



yoyn'3 y:lys ?hys::i:yy 



prevent its flowing in any other. They are operated by 
slender but powerful muscles within the ventricles. 

The valve on the right side of the heart is called the 
three-pointed or tricuspid valve. 

That on the left is said to look like a bishop's mitre : 
hence it is called the mitral valve. 




Between the ventricles and the arteries are the semi- 
lunar valves, so called from their shapes. 

The valves fall back to let the blood flow from the 
auricles into the ventricles, but float up with the blood 
so as to prevent the return of the blood into the 



THE BLOOD AND ITS CIRCULATION I3I 

auricles. They are prevented from floating over into 
the auricles by delicate cords which tie them to the 
ventricles. 

109. Blood-Vessels connected with the Heart. — 
The aorta, which is the largest artery in the body, 
springs from the left ventricle. It carries the bright, 
pure blood out from the heart. 

Four pulmonary veins open into the left auricle. Two 
of these veins come from the right lung, and two from 
the left lung. They bring back to the heart the blood 
which has been purified in the lungs. Two of the 
largest veins in the body, called the superior and infe- 
rior vena cava, open into the right auricle. Both of 
these great veins pour into the right auricle, the dark, 
impure blood, which has been collected in various parts 
of the body by the smaller veins. 

The pulmonary artery springs from the right ventricle. 
Soon after leaving the heart, it splits into two pipes ; 
one goes to the right lung, the other to the left lung. 
This artery carries from the heart to the lungs the dark, 
impure blood, which has been brought to it by the great 
veins. Its entrance is guarded by the semilunar valves. 

1T0: The Arteries. — The arteries are the pipes 
which carry blood from the heart to all parts of the 
body. 

The arteries may be regarded as branches of the 
aorta, or the main artery, which starts from the left 
ventricle of the heart. After leaving the heart, the 
aorta rises towards the neck, but soon turns downwards 
forming a curve, called the "arch of the aorta." This 
great pipe, passing between the lungs to the back, then 



132 YOUNG FOLKS PHYSIOLOGY 

runs down along the spine, through the diaphragm. In 
tne lower part of the abdomen, it divides into two main 
branches, one of which goes to each lower limb. 1 

Two large arteries spring from the arch of the aorta, 
and run up on each side of the neck to the head. 2 Again 
there are two large arteries, which branch off from the 
aorta, pass beneath the collar-bone, and supply branches 
to the arms. 3 

While the aorta is passing down the spine, it gives 
off branches to the important organs of the abdomen. 

in. The Veins. — The reins are the return-pipes 
that bring the blood back to the heart. 

Unlike the arteries, which gradually grow smaller 
and smaller, the veins, starting from the capillaries, 
grow continually larger and larger. The veins of the 
legs travel upwards, becoming gradually larger by the 
addition of other branches in the abdomen, until at last 
all the united branches are joined in one great vein, 4 
which empties into the right auricle of the heart. The 
venous blood from the head and arms flows back, and 
empties into the right auricle by another large vein. 5 

Veins generally lie near the surface of the body, just 
beneath the skin. We may see them in almost any part 
of the body. 

The veins are abundantly supplied with little pouch- 
like folds, or pockets, which act as valves, and allow the 
blood to flow only towards the heart. If we press 
the fingers along one of the veins in the arm, towards 
the hand, we shall see a number of little knots, or 

1 Femoral. 2 Carotid. 3 Subclavian. 

* Inferior vena cava. 5 Superior vena cava. 



THE BLOOD AND ITS CIRCULATION 133 

swellings, here and there along the vein. The blood 
thus forced back fills the little pockets in the vein. 
Take away the finger, and the knots will at once disap- 
pear, because the blood is left free to flow towards the 
heart. 

112. The Capillaries. — Between the end of the 
smallest arteries and the beginning of the tiniest veins, 
is a very close network, like the finest lace, with the 
minutest little tubes for threads. These little tubes 
are the capillaries, or hair-like vessels. 

In reality, they are as much smaller than hairs, as 
hairs are smaller than cables. So closely set are these 
tiny vessels, that we cannot prick any part of the skin, 
even with the smallest needle, without wounding one 
or more of them, and drawing blood. Some of them 
are so small that three thousand of them placed side 
by side would not, in their united width, measure more 
than one inch. The blood corpuscles can only pass 
through them in single file. 

The Yeins compared to a Sewer System. — As we compared the 

arteries to the water-supply pipes of a great city, we may now compare the 
veins to another underground network of pipes, commonly called the 
" sewer system." The pure, wholesome water is brought by the street 
pipes to each house. It is used, becomes filthy with dirt, waste, and all 
kinds of impurities ; then the drains from each house carry it off before it 
can do any harm. The sewer-pipes from the houses unite with those 
of the streets ; those of the streets unite at last into one great main sewer, 
through which flows this unwholesome river of impurities. 

The veins of the body resemble this sewer system. ■ The pure, whole- 
some blood is brought by the arteries, is used by the tissues, and becomes 
foul with impurities. The veins are the drain-pipes of the body which 
carry away this impure blood from the tissues, and spread out their 
contents into Nature's great purifying reservoir, the lungs. 



:. : - 





YOUNG FOLKS PHYSIOLOGY 

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THE BLOOD AND ITS CIRCULATION 



135 



into the right ventricle lies open, through which the 
blood flows until it is full. The ventricle now begins 
to contract ; the tricuspid valve at once closes, and 
thus prevents the reflow 
of blood. The blood is 
driven into the pulmo- 
nary artery through the 
semilunar valve. 

This artery carries the 
blood to the lungs. The 
dark, impure blood is 
driven along narrower 
and narrower vessels 
until it reaches the cap- 
illaries of the lungs. 
Here it is, as it were, 
spread out to be purified. 
Exposed to the oxygen 
of the air, the blood gives 
up its impurities and its 
purple look. 

It takes up a great 
deal of the oxygen of 
the air in exchange ; and 
in a purified state, and 
of a bright scarlet color, 
it comes back to the heart by the pulmonary veins, 
which pour it into the left auricle. 

From the left auricle the blood is forced through the 
mitral valve into the left ventricle. As soon as the left 
ventricle is full, it begins to contract. The mitral valve 




Fig. 51. — Diagram of the Arterial System. 



I3« 



YOUNG FOLKS PHYSIOLOGY 



at once closes, and blocks up the passage into the left 
auricle ; and the blood has no other way open but 
through the semilunar valve * into the aorta. 




Fig 52. — Arteries of the Neck and Head. 



The aorta and its branches, as we already know, dis- 
tribute the blood through every tissue of the body. 
From the tissues it is again returned by the veins to 



1 The entrance to the aorta is guarded by a semilunar valve similar to that at 
the entrance of the pulmonary arteries. 



THE BLOOD AND ITS CIRCULATION 1 37 

the right auricle of the heart, and thus the round of 
circulation is continually kept up. 1 

114. Sounds of the Heart. — As the heart is doing 
its work, it gives out certain sounds. If we put our ear 
against the chest of another person, over the region of 
the heart, we can easily hear two " pit-pat " sounds, one 
longer than the other. The first sound takes place 
when the walls of the heart contract, and force out the 
blood. The sharp, second sound is heard when the 
doors, or semilunar valves, shut. 

When the ventricles contract, the apex of the heart 
strikes against the wall of the chest, on the left side, 
between the fifth and sixth ribs. This is known as the 
" beating " of the heart, which makes itself felt when 
unusually strong, as in running and jumping, or during 
any other severe exercise. Sudden joy or fear will also 
make the heart beat quickly. 

Thus, while we cannot make the heart go slower or 
faster by any effort of the will, it is greatly influenced 
by the feelings. 2 It is quickened by mental excitement ; 

1 A drop of blood goes the grand round of the body in about twenty-two sec- 
onds ; that is, while we are counting twenty-two, the blood flows through the 
right side of the heart, passing out into the smallest capillaries of the lungs, is 
purified, absorbs oxygen, is picked up again by the veins, and returned to the left 
side of the heart, to be driven out through the arteries into the capillaries, picked 
up again by the veins, and returned to the right side of the heart, — thus making 
the grand round. The entire blood in the body is thus able to make this complete 
circuit in about two minutes. 

2 People who work hard and are poorly fed, often suffer from an irregular 
beating of the heart after some exertion, as walking up a steep hill, or going up- 
stairs, or sweeping. The feeling is as if the heart were going to " jump out," and 
is commonly known as " palpitation." It is purely a disturbance of the functions 
of the heart, and has in no wise to do with heart disease, from which people die so 
suddenly. Palpitation of the heart is occasionally caused by long-continued 
drinking of strong tea and coffee. Tobacco will often bring on the same trouble. 
Thus we have the " tea-drinker's heart " and the " tobacco heart." 



I3<5 YOUNG FOLKS PHYSIOLOGY 

while a sudden shock to the mind may cause such a 
failure of the heart's action as to cause fainting, and in 
very rare cases death itself. 

115. The Pulse. — If the finger be put over an artery 
which lies near the surface of the body, like the radial 
artery, for instance, near the wrist, or the temporal ar- 
tery, just over the temples, a regular throbbing, called 
the pulse, will be felt. 

This is the reason for it : when the left ventricle con- 
tracts, the blood is forced into the arteries, already full 
of blood, faster than it can pass through them. The 
elastic arteries are stretched by the extra blood ; and 
their rhythmical throbbing, keeping time with the heart 
beat, is felt by the finger. 

In a healthy grown person, the pulse beats about 
seventy-two times a minute. In children the pulse is 
quicker than in adults, and slower in old age than in 
middle life. As the pulse varies very much in its rate 
and character in disease, it is to the trained touch of 
the physician a good index of the bodily condition of 
his patient. The pulse is commonly felt at the wrist 
simply because that is the most convenient and acces- 
sible ; but it may also be felt at any place in the body 
when an artery runs near enough to the surface. 

116. Effect of Alcohol on the Circulation. — The 
flushed face of the drunkard, or even that of the moder- 
ate drinker, is an every-day sight. It may seem to him 
and to others a sign of health, but it is really one of the 
many symptoms of alcoholic poisoning. The alcohol has 
deadened the nerves which regulate the flow of blood. 
The walls of the blood-vessels stretch, thus allowing 



THE BLOOD AND ITS CIRCULATION 1 39 

more blood to flow through them. The arteries are 
relaxed, the capillaries are engorged with blood, and the 
undue amount of blood shows through the skin, making 
it look red. 

This action, — medical men call it " congestion," — 
we must remember, is not confined to the vessels near 
the surface of the body, but really extends to every or- 
gan and to every tissue. 

117. How Alcohol gets into the Blood. — Alcohol 
passes into the blood by two distinct routes. When we 
take alcoholic liquor into the stomach, some of it at 
once soaks through the coats of the tiny blood-vessels 
with which the lining of the stomach is covered, and is 
carried into the blood-current by the portal circulation. 

Alcohol is also taken up by the lacteals, and is emp- 
tied into the blood through the thoracic duct. Now, 
although alcohol goes to the heart, to be sent to every 
part of the body in a roundabout way through the liver, 
it takes only a moment or two for it to get into the 
main blood-stream. A glass of strong drink soon "goes 
to the head," as many people know ; showing that its 
effects are rapidly produced in the remotest tissues of 
the brain. The rapidity of this absorption depends upon 
the kind of liquor and the condition of the stomach. 

Alcohol thus taken into the blood is flushed every- 
where, — into each fibre, membrane, and tissue. It 
saturates all the vital organs, of the brain, heart, liver, 
lungs, kidneys, skin, and the secreting-apparatus. 1 

1 " The habitual use of alcohol produces a deleterious influence upon the whole 
economy. The digestive powers are weakened, the appetite is impaired, and the 
muscular system is enfeebled. The blood is impoverished, and nutrition is im- 
perfect and disordered, as shown by the flabbiness of the skin and muscles, 
emaciation, or an abnormal accumulation of fat." — Dr. Austin Flint. 



:_i: v:v\3 fuss ?:-:ys::i: :-y 

::5 Ere;: :: A:::h:: u::- :he Blcci. — I: ?. s-~- 



:~e ': : £y - 



r . -' .-. _.e Z'i ~.~:jy~~~ '.'.- 
jure. Waste matter 

:.~e ;:; rri: :: i-ieer 
::::.^::.r :: izirure 



7 s :i: ~-y :t iep:s::ei :_-_ : :.t muscles heirT. mi 
other places where it is not needed, and may slowly 
:::■-:. ur:~ mi :ike :*-e ;li:e :: :"~e rissues :: -.vhich 
:..:- rr^ins ire ::~r:se£ Tie :i: ::i-:: perf:r~ 
the work of the tissue it displaces, and disease is the 
result. The blood of the beer-drinker becomes unduly 
thin, and destitute of the material for forming a clot 
in case of wounds. Slight cuts may result in dangerous 

119. Effect of Alcohol upon the Heart. — The para- 
Ivzir.^ efir;: :: iizzi:'. : . :"~e nerves "r~i;h rer/.'.. : .:e 
the flow of blood in the arteries causes them to lose 
their grip on the blood-vessels, and hence the heart has 
tss res:s:ir.:e :: nee: .:::::::::';' i: is ::r:ei :: 
beat faster, and work harder, to fill the dilated vessels 
with blood.* "The alcohol paralyzes other nerves whose 
office is to hold the heart in check and to keep it from 
beating too last. Its effect is like that of taking the 
weight off the pendulum of a clock : it beats wildly and 
rapidly, without anything to control it. This increased 
frequency of the heart's stroke results in increased la- 
bor, more wear and tear, and less rest for this vital organ. 

1 See Note 15, page jffu 

l Z'-.t 'i-r I : Pir'ii-s I" := -■:-: Z~ : .--. i-f ::.:j :" -^r.in : r.-^:-' zL- 
;_•_,-.£: ;:: i;T:; : -:i :: :t - iis: -'-.t- i :.-.:"- : '- : -'5 -ere ::-«-- si. 
j_- .-:;•:: :-.t '..:::- z ::' :^tr. :"-:': : ::=.? . : t-.:ri :'.:■:•! . "t :':•:: - ;'-. ei:-. iav. 
— 1:.: .: ■.-»:.-:/ 7^.: :t": ::' iii.z:-il -■ ::*. 



THE BLOOD AND ITS CIRCULATION I4I 

It has been estimated that the amount of extra work 
which alcohol puts upon the heart is equal to the work 
of lifting from five to thirty tons, according to the amount 
taken, one foot high in the course of twenty-four hours. 
This effect of alcohol is often called its stimulant action. 
It is more exact to call it the beginning of the poison- 
ous action of alcohol. 

Here is the whole story : — 

Alochol causes an increase of action by narcotizing 
the nerves which regulate the heart. 1 

120. Effect of Tobacco on the Heart. — Tobacco 
causes irregularity and palpitation of the heart, fre- 
quently accompanied with attacks of severe pain. 
Physicians report many cases of heart disease among 
young boys, brought on by the use of tobacco. 2 A cele- 
brated physician says it invariably produces a weak, 
tremulous pulse. A German physician says that 
in his country, while even immoderate smoking may 
appear to agree with persons for many years, suddenly 
and without any other assignable cause, trouble with 
the heart begins. Leading physicians in our own 
country agree that tobacco is the true cause of a 
great proportion of the fatal cases of heart diseased 

1 See Note 16, page 2,73- 

2 " Tobacco, and especially cigarettes, being a depressant upon the heart, should 
be positively forbidden." — Dr. J. M. Keating, on " Physical Development," in 
Cyclopcedia of the Diseases of Children. 

3 See Note 17, page 374. 



142 YOUNG FOLKS' PHYSIOLOGY 

CHAPTER IX 

BREATHING 

121. Why we Breathe. — X'i'i: in: iav. wiihout :r.e 
moment's rest, from the first to the last instant of our 
lives, we are breathing. About eighteen times every 
minute, more than twenty-four thousand times every day, 
and many millions of times in a lifetime of seventy 
years, we draw in and send out again our breath. 

Most of the time we do not think anything about it. 
We eat, talk, work, and sleep ; and all this time our 
breathing goes quietly on. Breathing is the plainest 
sign by which we judge a person to be alive who lies 
otherwise motionless and insensible. Though we can 
hold our breath for a short time, yet, after a few seconds, 
we begin to feel uncomfortable. 

In speaking of food and the blood, we have learned, 
that, without food and fresh air, the burning, or oxidation, 
which is slowly going on in our bodies all the time, 
would soon flag, and we should, after awhile, die for want 
of them. Hence we must have oxygen to keep the 
burning. We get the oxygen from the air we breathe. 

Again : we have learned that the dark, impure, and 
venous blood was sent to the lungs from the right 
ventricle, and was returned to the left auricle as pure 
arterial blood of a bright red color. The blood has got 
rid of its waste matters, and becomes pure. In brief, the 
blood has been oxidized in the act of breathing. 

H ence in breathing we have two objects in view, — 



BREATHING 



143 



First, to bring a fresh supply of oxygen to the blood, 
by means of the lungs. 




Fig. 53. — Showing the relative position of the Heart, Lungs, Liver, etc., with reference 
to each other and the chest-walls. 

Second, to get rid of carbonic acid and waste matters 
taken up from the tissues, and brought to the lungs by 
the blood. 



144 YOUNG FOLKS PHYSIOLOGY 

122. The Air-Passages. — The air is drawn into the 
lungs through the mouth, nostrils, and windpipe. 

The nostrils are really the passage-ways for the air, 
and warm the air somewhat before it goes into the 
lungs. The air passes from the nostrils into the wind- 
pipe, or trachea. 

The windpipe is a hollow tube about four inches long, 
and is protected on the front and sides by stout rings of 
gristle. But for them the windpipe would close with 
the slightest pressure, and cut off the breath. The top 
of the windpipe is protected by a trap-door known as the 
epiglottis. When food is swallowed, this little door 
shuts tight, and keeps it out of the air-passages : other- 
wise the food would go the wrong way, and cut short 
our breath. When we breathe, the lid lifts up. 

The upper part of the windpipe is a kind of box called 
the larynx, or organ of voice. In this box — which in 
some persons is very prominent, and the front of which 
is commonly called "Adam's apple" — are the vocal 
cords. These cords are not strings, but rather elastic 
strips, with free edges which can be made tight or 
slack. As the air goes to and from the lungs, through 
the narrow slit between them, called the glottis, it sets 
the cords to vibrating, and thus makes the sound of the 
voice. 

The windpipe, after entering the chest, divides into 
two branches called bronchi, or windpipe tubes, sending 
one to each lung. These, again, divide into smaller 
tubes called bronchial tubes. Each bronchial tube divides 
again into smaller branches, these again into smaller, 
and so on to the tiniest twigs, a hundred times smaller 
than the hairs of our head. 



BREATHING 



45 



If we only remember that all these tubes, great and 
small, are hollow, we may compare the whole system to 
a short bush or tree growing upside down in the chest, 
of which the windpipe is the trunk, and the bronchial 
tubes the branches of various sizes. 

123. The Lungs. — The lungs are two large, pinkish, 
spongy organs, which 
surround the heart, and 
fill up all the rest of the 
chest-cavity. 

The right lung is the 
larger of the two, and 
has three parts, or lobes 
The left lung has only 
two lobes. The inside 
structure of the lungs 
is really a mass of air- 
passages, arteries, veins, 
and capillaries. 

Imagine athick, short 
tree crowded with leaves : imagine 




Fig. 54. — Ciliated Epithelium from the Human 
Trachea (magnified 350 times): a, innermost layers 
of the elastic longitudinal fibres ; b, innermost 
layers of the mucous membrane ; c, deepest round 
cells ; d, middle elongated ; e, superficial, bearing 
cilia. 



the trunk and 



How Nature protects the Air-Passages. — The inside walls of the 
windpipe and air-tubes are lined with a mucous membrane, which secretes 
a thick, sticky fluid called mucus, to keep the passages moist. This 
membrane is covered with thread-like processes called cilia. • They 
are not unlike fine hairs, and resemble somewhat the pile on velvet. 
They wave to and fro, like a field of grain in the breeze. 

The motion is always upwards and outwards towards the mouth. 
They make one continuous brush, which is ever busy sweeping out the 
air-tubes. They sweep up the particles of dust and mucus from the tubes, 
and brush them out of the pipes with a sudden blast of air which we call 
coughing. These tiny cilia are simply the dusters which Nature uses to 
keep the air-passages neat and clean. 



I-if YOTJTCJG folks" physiology 

mmmrs 5~m mi mem i :--- :: me mrnes: :mm. ire 
hollow. Supr ose the leaves the m selves w ere tiny blad- 

--*= :-:~"~ _r: mi riei m :: me s~mes: z:'l:w -.sirs. 

=--- ~ i---; -- s:~e iemme :.:: verv em::: 5 ms:m : e 

v •■ - = =5 Ar ::i: sum 1 : : 1 ~ e • 

. ^ f |±j f * work of hollow branches, 

: .-*fSffe :mei ::mmm rmes. 

* ^ ^> ^^k a»d hollow, elastic biad- 
; : ;"^ Vii :m| ders, called air-cells, is 

; --1^/ r| : ;% ■■-■-;-;:t.: im.e: : - -: -- 

I V --"^^':A\ network of arteries or 

^ Imagine 1 child's ball 

Sm If ^ ^|f : "- ; -^ --""-"-- "•' : : -•- ^ - " - - - : - 

• || ^Sr m; ::' rei mi mm 

- : ; ■-: s : • • : » 5 VaUL 

We can form some idea 

:: me -mmer ::' :;.: iir- 
zt'ls -r'ztz -*± re~ermer :*m: me eni :f me smmes: 
bronchial tube, often called a lung-sac, 1 is said to hold 
mm: sevemeer. mmrei m-:em 7m '. . m - ; mer. 
consist of millions of these tiny air-cells, packed closely 
together, each air-cell communicating with the wind- 
rme. mi 5: wizz me m:\ mmrr :.- m::~ ~e ::r::h: 

The chest is lined, and the lungs covered, with a 
s~ ::m i±'.:zzz± m::m :mei :':.: /.'..".: These :m 
5 mm :es rm mmm em~ mer mm "m meime 








BREATHING 147 

This lining secretes a fluid which keeps the parts 

always moist, and prevents their rubbing one on 
another. 




Fig. 56. — Section showing the ramifications of the Bronchi in the Lungs. 

124. How We Breathe. — If we put both hands on 
the sides of our own chest, and breathe in deeply, we 
feel that the act has carried the hands farther apart. 
Again, if we put one hand across the middle of our 
chest, we feel that it is carried forward every time we 
breathe in, and is returned to its place as we breathe out. 

Further, if we ( pass a tape-measure round the chest, 
and draw it tight when we breathe out, we find that the 
tape must be let out two or three inches when we begin 



I48 YOUNG FOLKS* PHYSIOLOGY 

to breathe in. If we breathe in and out with a great 
deal of force, the changes are more marked. 

Hence there are two movements in breathing, — one 
in which the cavity of the chest is made larger in all its 
dimensions : this is when we breathe in air, and is 
called inspiration. 

The other movement is the one in which the chest- 
cavity is made smaller in like manner : this is when we 
breathe out air, and is called expiration. The means by 
which the air is breathed in and out of the lungs makes 
up the act of breathing. 

125. The Act of Breathing. — The cavity of the 
chest is a closed air-tight chamber, whose only opening 
is the windpipe. The pressure of the air in the air- 
passages keeps the lungs stretched out so as to fill this 
cavity. Imagine now such a chamber as this to have a 
kind of false floor, capable of moving up and down. 
When the floor was crowded down, the cavity would be 
enlarged ; and the pressure of the air would then cause 
the elastic lungs to expand to a greater extent to fill up 
the extra space. 

When the floor was raised again, the cavity would be 
diminished ; and the stretched lungs, being diminished 
also, would give up the extra quantity of air which they 
took in. 

Suppose these two movements were performed at 
regular intervals. Then, every time the floor was 
pressed down, there would be a rush of air down the air- 
passages to the lungs ; and, every time it was raised, 
that same quantity of air would be driven out of the 
lungs again. 



BREATHING 



149 



This is exactly what happens during the process of 
breathing. The bottom, or floor, of the chest, is 
formed, as we know, by a large, flat muscle called the 
diaphragm. 

When this muscle contracts, it is pressed down, and 
the cavity of the chest is enlarged. When it relaxes, 
and consequently rises again, this chamber is dimin- 
ished. These two up-and-down movements of the 
diaphragm are the chief movements in ordinary, quiet 
breathing. 

The cavity of the chest, how- 
ever, is enlarged in another way. 
The walls of the chest are 
formed by the ribs, which en- 
circle it so as to join the breast- 
bone in front. The spaces 
between the ribs are occupied by 
a set of strong muscles called 
the intercostal muscles. 

One set of these intercostal 
muscles contracts, and pulls up 
the ribs, which are fastened to chial Tubes of the Lungs * 
the backbone behind by a joint. When the ribs are 
raised, they push out the breast-bone in front ; and thus 
the cavity of the chest is enlarged all round. This 
enlargement by means of the side walls takes place at 
the same time as the diaphragm descends, so that the 
chest is enlarged on all sides. An extra quantity of air 
then rushes into the lungs, and we get an inspiration. 

Immediately following the inspiration, the diaphragm 
relaxes, and, of course, rises ; and, at the same time, 




Fig. 57. — The Air-cells and Bron- 



I50 YOUNG FOLKS PHYSIOLOGY 

another set of intercostal muscles begins to pull the 
ribs and breast-bone down. These combined move- 
ments diminish the cavity of the chest, and conse- 
quently the same quantity of air is driven out. This 
makes an expiration. 

126. Changes in the Air from Breathing. — Air is a 
mixture of two gases, — oxygen and nitrogen, — in the 
proportion of one part of the former to four of the lat- 
ter. Oxygen is the active gas, the feeding and warming 
gas, the life-giving principle of nature. It has been 
well named " the great supporter of animal life." 
Nitrogen is mixed with it, lest the oxygen should be 
too strong for us, and burn us away too fast. In short, 
Nature dilutes the oxygen of the air for us with nitrogen. 

If we examine the air just as it enters the lungs, and 
again after it has passed through them, we shall find 
that, while the bulk is almost exactly the same, the 
quality has been changed. It has left behind about 
one-twentieth of its oxygen, and taken in exchange for 
it nearly the same quantity of carbonic acid. About 
twenty cubic inches of air pass in and out of the lungs 
with every breath, and about three hundred cubic feet 
every twenty-four hours ; amounting to the contents of 
sixty barrels. 

Let us try to understand how this interchange takes 
place between the air and the blood in the lungs. 

Experiments carried on outside of the body prove 
that gases can pass through delicate membranes. If 
a bladder is filled with oxygen, and then hung up in a 
bottle filled with carbonic acid, the two gases will mix 
with each other. The oxygen will pass out through the 



BREATHING 1 5 I 

walls of the bladder, and the carbonic acid will pass in. 
This is in accordance with a well-known law of physical 
science. 

This is practically what happens in our lungs every 
moment of our lives. The blood and the air are sepa- 
rated only by the thin and delicate walls of the air-cells, 
and by the walls of the capillary blood-vessels of the 
lungs. The matters contained in the blood pass out- 
wards into the lung, whilst the matters contained in the 
lung pass inwards to the blood. This last-mentioned 
act constitutes the essential feature in the function of 
respiration. The blood, thus renewed, travels to the 
left side of the heart, is pumped out through the aorta, 
and distributed to every tissue of the body. 

We may, in brief, look upon the lungs as a kind of 
market-place or exchange, where two merchants — the 
blood and the air — meet to exchange their wares. 
Indeed, it is a very busy market-place. 

This, then, is the whole story, shortly told, of our 
constant need of air : The tissues of the body, of 
whatever kind, everywhere over the body, breathe 
blood, making pure arterial blood venous and impure, 
in every part of our bodies, except in the lungs, where 
the blood itself breathes air, and changes from impure 
and venous to pure and arterial. 

The air, as it leaves the lungs, is saturated with 
watery vapor. This is seen when we breathe on the 
bright steel blade of a pocket-knife, a mirror, or any 
cold, polished surface. As we all know, the surface 
becomes covered with a thin film, or minute drops of 
water. In cold weather this moisture becomes visible 
with each expiration. 



152 YOUNG FOLKS PHYSIOLOGY 

Air as it leaves the lungs is much hotter than the 
surrounding air. It is generally about 98 F. For 
this reason, on a cold day we blow our fingers to warm 
them. The air breathed out of the lungs also contains 
a small amount of decaying animal matter. Every one 
knows the unpleasant odor of the air in rooms in which 
many persons have been closely shut up. 

127. Carbonic Acid and Its Poisonous Effects.— 
Carbonic acid, in its pure state, acts as a deadly poison. 
An excess of it in the air produces poisonous effects. 
The air we breathe out contains four parts in a hun- 
dred of this gas. Increase this to ten parts, and it will 
prove a deadly poison to warm-blooded animals. In 
smaller quantities this gas produces labored breathing, 
dizziness, headache, and *a general stagnation of the 
bodily life. 1 

In the mines this gas becomes the dreaded "choke- 
damp." It is dangerous oftentimes to cross over a vat 
in which beer is actively fermenting; for the air over 
the vat, loaded with carbonic acid, is utterly unfit to 
breathe. 

In the open air we rarely suffer any ill effects from 
carbonic acid, for the simple reason that Nature is 
always mingling the gas with the oxygen by means 
of the winds and the rains. A fresh supply of pure, 

1 This same deadly gas sometimes flows naturally from the earth. Some of 
us have heard of the " Valley of Poison " in the island of Java, of which fabu- 
lous stories are told by travellers. This gas is very abundant in this valley, 
and from its weight sinks to the ground, where may be seen, it is said, the skele- 
tons of birds and animals, which have been suffocated in their attempt to cross 
this death-trap. There is a lake in Italy called Avernus, meaning "without 
birds." As the story runs, birds, in flying over the lake, are poisoned by the 
carbonic acid, and fall dead into the water. 



BREATHING 153 

life-giving air is thus furnished in the greatest abun- 
dance. 

Like a prudent manager, Nature utilizes the car- 
bonic acid as the life-food of the vegetable creation. 
The trees, the plants, and the grasses make, as it were, 
oxygen out of the carbonic acid; while we make car- 
bonic acid out of the oxygen taken into the lungs. 

128. Impurities in the Air. — While carbonic acid and 
the waste animal matter given off with it from the 
lungs, are the most common impurities, there are many 
other things which make the air unwholesome. The 
poisoned air due to cesspools, drains, and sewers, is 
often a frequent source of disease. 

Sewer-gas is a fruitful source of certain diseases, as 
typhoid-fever and diphtheria. The foul air from chemi- 
cal works, bone and soap factories, and many other 
manufacturing places, is more or less hurtful to health. 
Even the dust in our rooms may carry, it is thought, 
the germs of disease. 

Certain occupations may shorten life by exposure to 
air loaded with impurities. Thus, there is the "miner's 
consumption," or "black lung," due to the dust breathed 
into the lungs, acting like so many little splinters in the 
delicate air-cells. Those who work on steel, emery, 
pottery, etc., also suffer from the irritating dust float- 
ing in the air. Other impurities are highly injurious 
to the lungs, as the dust in match-factories, white-lead 
works, copper and brass founderies, and arsenic in wall- 
papers. 

Unwholesome as the air may be in the workrooms of 
many trades, the real danger, after all, and that which 



154 YOUNG FOLKS PHYSIOLOGY 

should be of more concern to the public generally, 



p e::e£ ezfezis ::' :rei:h- 

':rei:he: The peril is 

:eir: : rrs. : ur s:h : :".- 

ii: :hur:hes. 



ir.srs :r:rr :he si: ^r mi .:. 
:._ lir ..: :h his ilreiiy : 
ir :ur :vru i: vir^-r: :rrs, 
:: :rrs hills, vestries :hei: 

129. How to Ventilate. — Tie best way to rid the 
air of its impurities is by some suitable system of y«- 
tilario». To ventilate a place is to cause pure air to 
flow through it. In other words, it is some practical 
riir ::• keep :he lir p ire iri ~h lies :rre Z: ;u:':ts: 
iri — e :irr:: keep :he lir :: ir.y :::::::f: r::r: is 
zure is :..: i:rr: sphere :u:siie 

The object aimed at in ventilation, is to give an out- 
ie: :; irrpure lir iri ir irie: :: :hi: -vhi:h is pure, 
fresh ir: r:::s: Rerrerrber :hi: i: is :::: i: iil :::::• 
sir. :hi: lir sh:uii be ::ii :: he pure The required 
amount of fresh air should be moved evenly through 
the room or building with a gentle current, and with- 
out a draught. 

An open fireplace is a healthful, safe, but not eco- 
nomical means by which to heat and ventilate a room. 
Stoves in a room, soon dry the air, unless fresh quanti- 
ties from outside are constantly supplied. When rooms 
are warmed by heated air from furnaces, the warm air 
should enter through registers in or near the floor, on 
one side of the room ; and impure air should escape 
through outlets in or near the ceiling, on the other side. 

Children should be trained from infancy to sleep 
with the windows partly open for the greater part of 
the year. Adult people in vigorous health should 
gradually learn to do the same. Even in the coldest 



BREATHING 1 55 

weather, some simple apparatus to let in fresh air is as 
good as any. Raise the window a few inches, and put 
in a piece of board under the lower sash. • Pure air will 
enter where the two sashes overlap. 

A common window-screen, cut to the proper size, 
and covered with flannel instead of wire, will let in 
plenty of air without draught, and is suitable for cold 
weather. Again, fit an^elbow of common stove-pipe 
into a board, of the right size, and put it under the 
raised sash, with a damper to regulate the current of 
air. These and other contrivances are easy to make, 
and cost but little. They answer the purpose even 
better than those that are more costly and complicated. 

130. Ventilation of Schoolrooms. — Special pains 
must be taken to ventilate schoolrooms. Pupils are 
sure to be listless, uneasy, dull, and sleepy when the air 
is not wholesome. Children may be comfortable in a 
well-aired room at 66° F., but it is very easy to let the 
temperature run up to 85 ° before it is noticed. What- 
ever the apparatus for ventilation may be, the doors and 
windows should be opened before and after each session 
and at recess. 

The air of the room should be changed as often as 
once every hour. The pupils meanwhile should engage 
in active gymnastic exercises to prevent taking cold. 
When this is done in cold weather, the heat should be 
turned on so as to warm the cold air coming in as 
quickly as possible. 

Weakly children, those liable to croup, those easy to 
catch cold and other ailments, must be carefully looked 
after. Never allow draughts of cold air to fall directly 



I56 YOUNG FOLKS' PHYSIOLOGY 

on the heads of children. Guard the air of the school- 
room from the foul air arising from closets, outbuild- 
ings, sinks, cesspools, and all other possible sources of 
ill-health. 

131. Why the Body is Warm. — Every one knows 
that the surface of the body feels warm. Hold the 
fingers in the mouth, and we find it warm. Put a 
thermometer, made for the purpose, in the armpit, or 
in the mouth for five minutes, and it will register about 
98 F., even in the coldest day of midwinter. This is 
the natural heat of a healthy person ; and it rarely 
varies more than a degree or two, except in disease. 1 

This heat is produced in just as simple a manner as 
that which results from a common fire or a lighted 
candle : it is the natural result of the process of com- 
bustion. We are warm ourselves, because we are burn- 
ing away bit by bit, just as a candle does ; that is to 
say, by the union of carbon, 01 charcoal, with oxygen. 
There is only this difference : we burn wet materials 
(the moist tissues), and do not make a flame or give a 
light. We take our coal or tallow in the shape of 
starch, sugar, and fat, and get the oxygen from the air 
we breathe. 

A steam-engine at work is warm because all the 
energy set free from the fuel burned is not turned into 
mechanical work, but some of it appears as heat : so it 

1 The rate of combustion may be much increased or lessened in various 
diseases. In pneumonia, typhoid-fever, and blood-poisoning, the physician may 
note a temperature of 105° F., or even more: hence the fever-patient says repeat- 
edly that he is " burning up " with fever, and eagerly drinks all the cold water 
which is given him, and calls for more in a few minutes. In other diseases, such 
as cholera, there is a notable fall in the natural temperature. 



BREATHING 1 57 

is in our bodies. Our muscles, our organs, in fact, 
every tiny cell, is busily at work ; and their substance 
is slowly burned at a low temperature. Every time we 
move, feel, think, or exercise any function, this oxida- 
tion, or burning, goes on. 

Some of the energy thus set free by this slow com- 
bustion shows itself as heat, which helps keep the body 
warm and at its natural temperature. Thus, animal 
heat is produced, and life maintained. Our bodies are 
working at a temperature higher than the surrounding 
air, except in the hottest weather : hence there must 
be a loss of heat nearly all the time. Therefore we 
must keep making heat all the time to compensate for 
the continual loss. 

Besides this loss by radiation, as it is called, consid- 
erable moisture is got rid of by the skin in the form 
of vapor, or sweat. The evaporation of this moisture 
from the skin acts as a kind of regulator to keep down 
the excess of heat. 



Proper Temperature for our Living-Rooms. — The temperature 
in our living-rooms should be kept at about 68° to yo° F. Most of our 
rooms are apt to be overheated or unequally heated, especially during 
cold weather. Any person, child or adult, may become tender and deli- 
cate in a short time by getting used to overheated rooms. The tempera- 
ture of the sick-room depends somewhat upon the age of the sick per- 
son, and his disease. A temperature of 40 to 50 F. may be suitable in 
typhoid-fever, while 8o° may be necessary for an aged person suffering 
from rheumatism. 

The greatest care in keeping any sick-room supplied with pure, fresh 
air, and at the proper temperature, is necessary. Old people generally 
need a higher temperature than the young and vigorous. The warm air 
in our living-rooms, to be wholesome, should be kept moist. A shallow 
pan of water put on the stove, or near a register, answers every purpose. 



I58 YOUNG FOLKS' PHYSIOLOGY 

132. Effects of Alcohol upon the Lungs. — The use 

of drinks containing alcohol tends to bring on inflamma- 
tion of the lung-tissues, and hence lessen the breathing- 
capacity. The tissues of the lungs become thickened 
and hardened by the alcohol, and hence do not allow 
oxygen to pass through them into the blood, and car- 
bonic-acid gas and other waste matters to pass out as 
they should. The apparatus called the " spirometer," 
used by life-insurance companies to test the breathing- 
capacity of lungs, often detects the dram-drinker by 
his failure to reach the natural breathing-capacity. The 
wheezy, broken speech of the drunkard is partly due to 
this condensation of the lung-tissue. 

Again, the repeated dilatation of the lung-capillaries 
tends to make the habitual user of alcohol more liable 
to attacks of severe cold, pleurisy, and pneumonia, 
after making due allowance for the exposure to cold 
and damp, so common with the intemperate. 1 

133. Alcohol and the Bodily Heat. — Soon after 
taking even a small quantity of alcohol, there is a gen- 
eral feeling of warmth over the surface of the body. 
The body is not really warmer, but the skin feels 
warmer. On the contrary, we are really colder, be- 
cause heat is more rapidly lost by radiation and evapo- 
ration from the surface. 

The skin is warmer after taking alcoholic liquor, 
because the nerves that regulate the hair-like blood-ves- 
sels on the surface, being partly paralyzed or deadened, 

1 According to some good medical authorities, the use of alcohol works such a 
change in the lung-tissues as not unfrequently to lead to a form of consumption 
called " alcoholic phthisis." 



BREATHING 159 

stretch and let more blood run through them. Hence 
more blood is sent from the central parts of the body 
to the surface. There is no real increase of heat : the 
surface is warmed for the time at the expense of the 
inner and deeper portions of the body. This surface 
warmth is now rapidly lost by radiation, and the gen- 
eral heat of the body is lowered below its natural tem- 
perature. The bodily temperature is regulated by the 
surface circulation ; and when this control is lost, as it 
is by alcohol, the body is cooled by the undue amount 
of blood carried to the surface. 

Experience has proved, time and time again, that 
alcohol lessens our power to endure extremes of heat or 
cold for any great length of time. Arctic explorers 
strictly forbid the use of alcoholic liquor among their 
men. It has been proved that the exposure to severe 
cold can be endured far better without alcohol. So 
well is this bad effect of alcohol known by the people 
of the coldest regions of Canada, that they will seldom 
take even a single glass of spirits when exposed to 
severe cold. 

Army life is perhaps the best possible test. It is the 
almost universal experience of British army officers who 
have led their men through the recent campaigns in 
the hottest parts of the Soudan, and who have given 
special study to the question, that alcohol, so far from 
being an aid to endure severe exertion and to resist 
great extremes of heat, acts as a positive injury. 

The notion that a dose of some alcoholic liquor taken 
after exposure or bathing will prevent one from taking 
cold, is erroneous. The alcohol, by irritating the deli- 



l60 YOUNG FOLKS PHYSIOLOGY 

cate lung-tissues and lining of the air-passages, and 
reducing the temperature of the body, makes one more 
liable to colds, coughs, pneumonia, etc. When one has 
been chilled, the best thing to do is to get thoroughly 
warmed, as quickly as possible, either by active exercise 
or artificial heat. 

Alcohol hi Hardship and in Extremes of Heat or Cold. — -I: 

was quite reruarkarie :: reserve it:~- ruutu srrtuuer auri utzre a'tie :: i: 
tieir vr:rk tie rue.a vrere -writer, titey "uari u tritiag tut vrater tti tiriak." — 

• A so] : liei as given a terraia amount of work to do, first when his 
svsreat was tree frtua :"ae eft'etts :: aittiati. auri settati T itea uatier tite 
ir.uuer.ee ::' terraia uaeasurea i:ses :: itrar.riv. Tite resuir is suuauueri 
■;.: is t:ii:~'s : Tite "rnr. riv seeuteti t: rue iaiaa :-.. ktr.i :t s - ;::: 
utir ituu titiuk ite ttuid a: t trreat ieai :t w:rk. "tut v.- iter, ite taaae :; 
t : '.'. tt t : ur. i ue ^ is .ess :t:t:.t tut r. te tut'Utut. »t: ercr. er.eute : : 
this man harmonizes with the advice that is given by guides and others 
who are in the habit of ascending mountains. Spirits, they say, take 
away the strength from the legs, and should therefore be avoided during 
a fatiguing expedition." — F. W. Pavy in " Food and Dietetics? 

The Army of the Potomac, in the spring of 1862, was subjected to 
great hardships in labor, and exposed to the extremely wet and mala- 
rious region of the Chickahominy. There was consequently much sick- 
ness and suffering. Under these circumstances the commanding general 
issued an order allowing every officer and soldier one gill of whiskey 
per day, half to be served in the morning and half in the evening. The 
results were so manifestly injurious to the sanitary condition of the army 
that in just thirty days the order was countermanded by the same 
general. Concerning this experiment, Dr. Frank Hamilton, one of the 
most eminent surgeons serving with that army, said, "It is earnestly 
desired that no such experiment will ever be repeated in the armies of 
the United States." 



HOW OUR BODIES ARE COVERED l6l 



CHAPTER X 

HOW OUR BODIES ARE COVERED 

134. The Skin and How it looks. — The skin is the 
outside covering of the body. 

The parts underneath are very tender and sensitive. 
We all know how painful and tender is any part of the 
body when the skin has been torn, cut, blistered, 
burned, or otherwise hurt by accident. Kind nature 
has given us a strong, elastic, and tight-fitting outside 
garment. It is easily kept clean, and never wears out. 
It is soft and thin, yet strong enough to enable us to 
come in contact with objects without pain or incon- 
venience. 

The skin is richly supplied with nerves and blood- 
vessels, so closely netted together that it is next to im- 
possible to prick the skin anywhere with the point of a 
needle without drawing blood, and feeling pain. 

135. The Scarf-Skin. — The skin is made up of two 
layers. The outer one has neither blood-vessels nor 
nerves, and is called the scarf-skin, cuticle, or epidermis. 

The lower layer is called the true skin, or cutis, which 
is richly supplied with nerves and blood-vessels. It is 
so highly sensitive, that, were it not for the scarf-skin, 
we could not endure life. Most of us are familiar with 
the delicate pink skin, very sensitive and very painful, 
which is exposed when the lowest layer of the outer 
skin is removed by a blister, or rubbed off by some 



162 



YOUNG FOLKS PHYSIOLOGY 



slight accident. The surface feels raw, and oozes a 
little clear fluid, or perhaps a little blood. 




Swral Claris 



Fig. 58. — A sectional view of the Skin (magnified). 



This is the deeper portion of the scarf-skin, which is 
constantly growing, and developing millions of little 
round cells to take the place of the flat, horny, and life- 
less scales of the outer portion, which are continually 
dropping off, or being removed by friction. 



HOW OUR BODIES ARE COVERED 163 

When these flattened scales are pressed together, 
they become flatter and flatter ; and thus the hard, 
horny skin is made, which is seen on the hands of those 
who use them in hard manual work. The "callus" on 
the hands of a blacksmith, carpenter, or washerwoman 
is a familiar sight Undue pressure or friction from 
poorly-fitting or tight-fitting boots and shoes causes the 
hard bunches on and between the toes which are com- 
monly known as " corns." 

In the deeper parts of the scarf-skin are tiny specks 
of coloring-matter, hid in little cells. It is this part of 
the skin that gives it its color, commonly called the 
complexion. In the fairer races, these specks are of 
a pinkish color : in the dark races, the pigment-cells 
are brown or nearly black, and more closely crowded 
together. The heat of the sun acts to darken these 
color-specks, as is seen in the parts of the body exposed 
to direct sunlight. 

We see every day the sharp line drawn between parts 
of the arm or neck exposed to the sun's rays, and other 
parts generally covered with clothing. Some, however, 
tan much more readily than others. When the pigment 
matter changes in spots, we call them freckles. There 
may be other defects, such as liver-spots, moth-spots, 
and other blemishes so often found on the skin. In 
slight burns, bruises, cuts, blisters, cold-sores, and many 
eruptions on the skin, the epidermis only is affected. 
Such injuries and diseases, therefore, heal without a 
scar. 

136. The True Skin. — The true skin, or cutis, is a 
firm, elastic tissue, resting on meshes of texture some- 



164 YOUNG FOLKS' PHYSIOLOGY 

thing like damp, raw cotton, which loosely fasten the 
skin to the parts beneath. It is the true skin which 
becomes filled with water in dropsy, and which, in the 
lower animals, is made into leather by the process of tan- 
ning. In this layer also are the sweat and oil glands, the 
hairs, nerves, blood-vessels, and absorbents of the skin. 

The outer surface of the true skin rises into little 
ridges called " papillae," into which the capillaries and 
nerves are distributed. These papillae are very numer- 
ous everywhere, but are the thickest where the sense 
of touch is most acute, as on the tips of the fingers, 
and on the nose. They are arranged in rows, like hills 
of corn, and are plainly seen with a magnifying-glass 
on the palms of the hands. 

When the true skin is destroyed, a scar results. 
White scars, especially on the hands, due to deep cuts, 
are common enough. Scars from small-pox, deep 
burns, and other injuries to the true skin, are often 
seen. The skin is rich in its blood-supply. The nerves 
are also very abundant. The prick of a pin, or the 
sting of the smallest insect, causes pain. 

How the Skin may absorb Poison. — The scarf-skin protects the 
skin from poisons. Lead, mercury, and other injurious substances will 
not enter the blood, and affect the bodily health, unless they are actually 
rubbed through the scarf-skin ; but if there is a scratch or sore, so that 
the true skin is exposed, the poisons may be absorbed into the blood 
with great rapidity. Workers in lead, looking-glass silverers, and phos- 
phorus-match makers ought, therefore, to take great care to cover the 
smallest scratch upon their hands. " Lead colic " and " wrist drop " are 
familiar instances of lead-poisoning. Cheap underclothing, as colored 
stockings, are often dyed with preparations of lead. Such articles should 
be thoroughly washed before they are worn. Many hair-dyes contain 
lead, and often cause lead-poisoning. 



HOW OUR BODIES ARE COVERED 165 

137. The Hair. — The hair and nails are simply por- 
tions of the outer layer of the skin altered in shape 
and structure. A hair is a slender thread of scarf- 
skin, which grows from little sacs in the true skin 
called " hair-follicles." Every hair has two parts, the 
root and the free end. The root is somewhat pear- 
shaped, and is sunk in its sac, or follicle, like a post 
into the ground. In the bottom of this sac is a little 
hair-papilla (quite distinct from the papillae of the skin), 
from which material for the life of the hair comes. 
As long as this papilla is not destroyed, the hair will 
grow. Pull out the hair " from the roots," and it will 
grow again. Destroy this papilla, and the hair never 
grows again. 1 

One or more little glands open into each hair-sac, and 
pour out an oily matter for its nourishment. The out- 
side of the hair is quite firm : the inside is softer, and 
carries the nourishing fluids. Hairs grow from cells 
pressed together lengthwise, so as to be drawn out into 
fibres, instead of being flattened into scales. Hence 
they grow only in length. On the outer surface the 
cells form a sort of bark, overlapping each other some- 
thing like the shingles on a roof. The coloring-matter 
is contained in these cells. When it fails, the hair turns 
gray or white. The hair-follicle is well furnished with 
nerves, hence it hurts to have the hair pulled. 

1 It is useless, or worse than useless, to try to rid one's self of unsightly 
hairs or hair-moles on the face. Pull them out with tweezers, cut or shave them 
off, and they are sure to grow again, coarser and more unsightly than before. 
All remedies advertised to remove superfluous hairs are worthless or dangerous. 
The hair-papillae must be destroyed to stop the growth of hair, and this is no 
simple matter. 



1 66 YOUNG folks' physiology 

The hairs, or rather the skin close to them, are pro- 
vided with the tiniest muscles. They run from the 
bottom of each hair-follicle in a slanting direction, and 
end in the outer part of the true skin. When they 
contract they cause the hair to stand more or less erect, 
and the skin to " bunch up " a little. Thus, at the sight 
of a dog, the hairs on a cat's back become erect and 
bristling. Any one who has been frightened suddenly, 
or has taken a chilly bath, knows what it is to have 
"goose-flesh." 1 

These muscles of the skin also act to squeeze oil out 
of the oil-glands. Hairs of some sort are found all over 
the surface of the body, except the palms of the hands 
and the soles of the feet. 2 They serve to protect from 
heat and cold the parts they cover. On the head, the 
hair helps to protect the skull from injuries, and the 
brain from extremes of heat and cold. On the body, 
they also help to drain off the sweat. 

138. The Nails. — The nails are only portions of the 
scarf-skin in a hardened form. 

They grow from roots which are lodged in a groove 
of the skin, something as a watch-crystal is fitted into 
its case. The part which is beneath the skin towards 
the hand is called the root, and the rest the body. The 
nail rests upon a bed, called the matrix, to which it is 
firmly fastened. Nails grow from the root ; and, as 

1 This idea of having one's hair " stand on end '' passed long ago into com- 
mon speech and classic literature. Compare Job iv. 15. 

2 The total number of hairs on an average head is estimated at about 120,000. 
The common diameter of an average hair is about ^ of an inch. The strength of 
the hair is much greater than one would suppose. A single hair has held a weight 
of nearly 2$ ounces without breaking. 



HOW OUR BODIES ARE COVERED l6j 

long as this is not injured, they are not lost or dis- 
figured by slivers, sores, blows, and bruises. 

Disease or injury of the root generally results in a 
badly-shaped nail. The nails serve by their horny 
texture to protect the outer portions of the ends of the 
fingers and toes from injury, and to give a support for 
the fleshy ends. 

Our finger-nails grow out about three times a year. 
They should be trimmed with the scissors once a week, 
leaving them long enough to protect the ends of the 
fingers. Nails should never be trimmed to the quick. 
They should not be cleaned with any thing harder than 
a brush or bit of soft wood. They should not be 
scraped with a penknife or anything metallic, as it 
destroys the delicacy of their structure, and will give 
them an unnatural thickness. 

" Hang-nails " are caused by the skin sticking to the 
nail, which, growing outward, drags the skin along with 
it, stretching it until one end gives way. To prevent this, 
the skin should be loosened from the nail once a week, 
not with a knife or scissors, but with something blunt, 
such as the small end of a tooth-brush, or the ivory 
instrument made for the purpose. 

139. The Oil-Glands. — The oil-glands are little 
round sacs, clustered together like a bunch of grapes, 
with a tube which opens into the hair-follicles. 

Generally there are two to each hair ; but in some 
places there are as many as four to eight around a 
hair, making a kind of collar about it. These glands 
furnish a natural dressing for the hair, and keep it 
moist and. glossy. They also keep the surface of the 



168 YOUNG folks' physiology 

skin soft and flexible, and prevent it from becoming dry 
and hard. In some places these glands, as upon the 
nose, chin, and forehead, are large, and the hairs very 
small ; hence it often occurs that they open directly 
upon the skin. In these the oil is likely to collect, 
and get hard. 

Bits of dust get into these glands, acting like plugs, 
and show themselves as small black specks, incorrectly 
called "flesh-worms," because of the resemblance which 
these little masses have to a worm. This oily secretion, 
which might well be called nature's hair-oil, is perfectly 
fluid in a healthy skin, and at the temperature of the 
body. 

140. The Sweat-Glands. — The sweat-glands consist 
of very fine tubes, about one-tenth of an inch long, 
coiled up into knots, from each of which a canal, called 
a sweat-duct, opens on the surface of the skin. 

The openings of these sweat-glands are arranged 
somewhat regularly, as may be seen by a common 
magnifying-glass, especially on the palms of the hands, 
between the ridges of the skin. On the sole of the 
foot and the palm of the hand they are very numerous, 
there being some three thousand of them to the square 
inch ; while on the cheeks there are only five hundred 
and fifty in the same space, and twelve hundred to the 
square inch on the forehead. There are about three 
millions of them, it is said, in the whole body ; and, if 
they were laid end to end, they would stretch to a dis- 
tance of three to four miles. 

These glands secrete the sweat, which is a colorless 
fluid, with a peculiar odor. It is a part of the waste 



HOW OUR BODIES ARE COVERED 1 69 

matter of the tissues, which has been filtered from the 
blood, and is got rid of through these busy little glands 
in the skin. They are always at work pouring out 
sweat, though it may not be evident to the eye or touch. 
In hot weather, or after violent exercise, it is much 
increased, and collects in big drops, which run away in 
streams. The average daily quantity of sweat is not 
far from two pints. It varies very much according to 
what we are doing, the condition of health, how we 
are clothed, and the temperature of the surrounding 
atmosphere. 

The object of this sweating through the skin is to 
regulate the temperature of the body by evaporation 
from the surface. We fan ourselves on a hot day to 
hasten this evaporation of the moisture on the skin. 
In hot weather, after taking hot drink or a hot-air bath, 
the skin does its best to reduce the temperature, and 
thus works all the harder in pouring out the sweat more 
profusely. When one is sweaty, it is highly imprudent 
to sit in a cool draught ; for this evaporation may be 
suddenly checked, and we are apt to take cold. 

It is now easy to see, that if this vast secreting-sur- 
face is hindered in its action by chilling it in a draught, 
by being too thinly clad, or by sudden changes in the 
weather, we may readily " catch cold," and cause a " con- 
gestion," as it is called, of certain internal organs, like 
the lungs, kidneys, or intestines. 

141. Why we should take Care of the Skin. — There 
are nearly three millions of sweat-glands in the skin, 
acting like drainage-tubes, nearly three miles long, 
together with the oil-glands, pouring out two pounds 



I/O YOUNG FOLKS PHYSIOLOGY 

daily of sweat, oil, and other used-up matters, through 
the hard-worked skin. The sweat evaporates, and 
leaves the solid and oily matters to plug the mouths of 
these tiny sewer-pipes. 

The dead scales of the scarf-skin are continually 
dropping off. They become sticky with the oil, and, 
getting entangled in the meshes of the clothing, be- 
come glued in a kind of thin crust to the surface of the 
body. This, if not regularly washed off, attracts the 
floating dirt and dust. Thus, the glands of the skin 
get choked up, and are not able to do their work 
properly. 

Other organs, such as the lungs and kidneys, have to 
do their own work, and that of the skin besides. The 
balance of health is disturbed, because the blood is not 
properly purified ; and disorders, especially of the skin, 
are almost sure to result. 

Hence we see both the importance and the real need 
of keeping our bodies clean and neat. The fireman is 
ever busy rubbing and polishing his engine, to rid it of 
the dust, oil, and dirt, and to make it bright, clean, and 
neat. He is thus able to have all the parts of the 
machinery running smoothly and without friction. 
Surely we should take as good care of our person, 
especially of its surface, which is always sifting out 
impurities, and getting clogged with dust and dirt. 

Finally, a filthy skin often becomes a breeding-place 
for the spread of those diseases and ailments which are 
" catching," such as scarlet-fever and measles, to say 
nothing of certain contagious disorders of the skin, by 
no means dangerous, but decidedly unpleasant. 



HOW OUR BODIES ARE COVERED I/I 

142. Baths, how and when to take Them. — The 
first object in using soap and water on the skin is to 
keep it clean ; the second, to give vigor and strength to 
the whole body. 

It takes very little time, expense, or bother to take 
a daily bath of some sort. A hand-basin, a sponge, a 
strip of cotton-flannel, a piece of castile soap, a gallon 
of water, and a towel, are all that are required. Even 
rubbing the body every day, first with a damp towel, 
and afterwards very briskly with a dry one, will, in 
most cases, keep the skin clean enough during the 
week, and give a healthy reaction, provided a bath with 
warm water and soap is taken at the end of the week. 

Whether the daily bath should be taken in warm or 
cold water depends upon circumstances. Most persons, 
especially the young and vigorous, soon get used to 
cool, and even cold, water baths. The point is, to get 
a brisk and rapid reaction before the "shivers" come 
on. If we shiver after a bath, instead of getting a 
warm, comfortable glow, warmer water should be used. 

The first effect of any cold bath is to shrivel up all 
the vessels of the skin, and make the surface pallid. 
Brisk rubbing should soon bring on a reaction, as it is 
called, in which the skin becomes red and full of blood. 
A feeling of genial warmth is felt all over the person. 
Always stop bathing if the shivering comes on, and use 
the towel vigorously until reaction sets in. 

Young children and old people, unless strong, vigor- 
ous, and well used to it, cannot take a cold bath with- 
out some risk. Like all other things, it may be weak- 
ening to carry bathing to excess. Very much depend? 



172 YOUNG FOLKS PHYSIOLOGY 

upon one's occupation and the condition of the skin. In 
some work, the grime, dust, and sweat must be washed 
off at least once a day, to feel at all comfortable, to say 
nothing of the health. 

Coarse and rough towels should always be used if the 
skin will bear it. Some skins are very active common 
sewers, which are ever sending out a large amount of 
waste matters. In such cases, a daily bath, especially 
in hot weather, is almost a necessity. Hot baths, with 
hot drinks, causing free sweating, helped on by wrap- 
ping the person snug in bed, with a jug of hot water 
or a hot flatiron at the side or feet will often save 
children and others from illness, if promptly and vigor- 
ously done after exposure to cold or wet. 

Swimming in running fresh water or in the sea has a 
wholesome effect on the skin, and is one of the health- 
iest of all exercises. Young people of both sexes 
should be taught to practise it whenever it is convenient. 
Never go in swimming when the body is overheated 
or very tired. Better sit down quietly, and cool off for 
half an hour. 

Many are drowned every year from ignorance or care- 
lessness in this one matter alone. The risk, of course, 
is from sudden cramps and colicky pains, which cause 
even a strong swimmer to sink like a lump of lead. 
For the same reason, it is not safe to take a swim just 
after a full meal. 

It is a good time for vigorous persons to take a cold 
bath just after getting out of bed in the morning. A 
bath at bedtime is refreshing, and favors sound sleep. 
There is little risk of taking cold if we go to bed at 



HOW OUR BODIES ARE COVERED 1 73 

once. Young and feeble children should bathe two or 
three hours after breakfast. 

It adds to our health and comfort to keep the hair 
clean. The oil-glands get clogged ; and dust and dirt 
rapidly make a coating on the scalp, and get entangled 
in the hair. Hence the hair should be washed, combed, 
and brushed, often and well. An occasional shampoo 
at home, with a wash made of the white of an egg and 
soapsuds, is healthful. Even a little borax dissolved in 
plain water, with vigorous rubbing, will do much to 
keep the scalp neat and clean. 

143. Why we need Clothing. — Clothes serve to keep 
up an even temperature about the surface of the body. 
In winter, they keep in the bodily heat, and protect us 
from cold. In summer, they shield us from the direct 
rays of the sun, and from excessive heat. The tempera- 
ture of our bodies varies only a few degrees at the most 
from 98^° F. In our climate, the outside air has a 
yearly range from ioo° or more in midsummer, to 20 
or more below zero in winter. We may even have a 
daily change of 20 to 40 F. The body is clearly 
much warmer than the surrounding atmosphere, and 
so it is continually parting with heat to the air. 

These frequent changes are a severe tax on the body. 1 
Without the protection of clothing, we could not endure 
the strain on the system. In short, clothing is our 
chief weapon of defence against the frequent changes 
of weather in our fitful climate. 

1 We often fail to recognize the danger of exposure to cold. One week's con- 
tinuous cold in London, it is said, adds over two thousand deaths to the usual 
average ; and they mostly occur among the poor, under-fed, and badly-clothed 
class of the population. 



174 YOUNG FOLKS PHYSIOLOGY 

144. Hints on the Use of Clothing. — Clothes should 

be changed according to the climate or time of year. 
It is not prudent to leave off winter clothing too early 
in the spring, for our seasons are most uncertain. 
Woollen should be worn next to the skin, whether in 
summer or winter. A most imprudent but common 
error of our daily living is to take off our winter flan- 
nels some day in early summer because it happens to 
be warm. With our sudden changes of temperature, a 
person may run great risk of taking severe colds, pneu- 
monia, and even " quick consumption." We should 
never allow ourselves to feel cold. If we cannot go 
where it is warm, or put on warm clothing, we should 
exercise until we feel warm. 1 

To keep our persons neat and clean, we must change 
our clothes often. This not only applies to garments 
used. for daily wear, but to bed-clothes and night-clothes. 
No one should sleep in the clothes he wears during the 
day. 

Under-garments should be frequently and regularly 
changed. All bed-clothes should be exposed freely 
to the light and air. Young children are less able to 
resist cold and sudden changes than grown-up people, 
hence great care must be taken in clothing them. 2 

The legs and chests of children should not be unduly 

1 " We should put off our winter clothing on a midsummer's day, and put it 
on again the day after. Only fools and beggars suffer from the cold ; the latter 
not being able to get sufficient clothes, the ethers not having the sense to wear 
them." — Boerhaave. 

2 The celebrated surgeon, John Hunter, gave three simple rules for the rearing 
of children ; and they are just as applicable to adults. They are, " plenty of 
sleep," "plenty of milk," and "plenty of flannel." 



HOW OUR BODIES ARE COVERED 1 75 

exposed to the bitter blasts of winter, nor the cold east 
winds of spring. Hundreds of children die every year 
from lung-diseases, due to ignorance or neglect in this 
matter. Never wear wet or damp clothes one moment 
longer than necessary. If you have on wet clothes, take 
the shortest way home, rub down thoroughly, and put 
on at once dry, warm clothes. 

Do not let your damp skirts, wet stockings or shoes, 
dry on you, but always change them at once if possible. 
Neglect of this precaution is a fruitful cause of rheu- 
matism and chest-ailments, especially among delicate 
people and young women. 

Do not wear the clothing too tight, and thus allow it 
to interfere with free movements and easy and graceful 
carriage, to say nothing of health. Garters and elastics 
worn below the knee are apt to hinder the circulation, 
and cause cold feet, and sometimes enlarged veins. 

Dresses and skirts should never drag their full weight 
from the hips, but should be supported from the 
shoulders. Health and comfort should not be sacrificed 
for any strange devices to dress the person in a slavish 
submission to any fashion. 

Teachers and parents should take the utmost care in 
the matter of children's clothing. See to it that they 
have on the proper outside garments on going out, and 
that they take them off on coming in-doors. 

Children, and older people too, should never run 
out-doors without proper covering for the head. Never 
allow pupils to sit in the schoolroom with outside 
garments on, such as waterproofs, gossamers, cloaks, 
rubbers, rubber boots, and leggings. 



I~6 YOUNG FOLKS' PHYSIOLOGY 

145. Effects of Alcoholic Drinks and Tobacco upon • 
the Skin. — Now, it is very evident that the skin, like 
any other active organ, depends for its nourishment 
upon the proper circulation of the blood. Hence, if 
this is interfered with by alcoholic drinks, the skin lacks 
its chief element of vitality. 

The effect upon the skin is soon evident. At first the 
skin has a peculiar soft, satiny feeling, from which saga- 
cious physicians have discovered the alcoholic habits of 
their patients, and perspiration is easily induced. Later 
on, the skin becomes thick and discolored, sometimes 
red and sallow. Dark-brown blotches begin to appear. 
Again, the skin is often affected with inflammations 
of various sorts, leading to many different kinds of un- 
seemly eruptions, boils, and abscesses. Alcohol often 
aggravates a skin disease, and tends to keep up the 
inflammation of any existing skin disorder, as salt- 
rheum, nettle-ra^h, and other ailments. 

The blood-vessels of the skin on the face, especially 
the nose and cheeks, become permanently stretched. 
The red and swollen nose, known as the " bottle-nose," 
due to alcoholic drink, is an every-day sight on the 
street. 1 

The effect of alcohol upon the bodily heat, in which 
the skin plays so important a part, has been discussed 
in chapter ix. 

The pores of the skin of a tobacco-user become sat- 
urated with the poisonous nicotine, giving the skin a 
peculiar dry and sallow look. 

1 " Frequent repetition of alcoholic drinks tends to permanently impair the 
activity of the circulation of the blood in the skin. Hence the visible vascular 
twigs and rubicund nose that characterize the physiognomy of the habitual 
drinker."— Dr. James C. Wils 



THE NERVOUS SYSTEM 1 77 



CHAPTER XI 

THE NERVOUS SYSTEM 

146. How all Parts of the Body work together in 
Harmony. — We have studied the human body as a 
kind of living machine. We have examined its various 
parts, and found them adapted to some special work 
essential to the well-being of the whole. 

Each organ not only looks after itself, but it is ever 
ready to come to the help of other parts of the body. 
Everywhere we find organs working together for each 
other's good. Strike suddenly at the eye, and the lids 
fall to protect it. Tickle the foot, and the muscles of 
the leg contract, and pull it away. When the skin is 
inactive, the kidneys come to its help. Fifty skilled 
mechanics might do their best at building a vessel or a 
house ; but if each man worked as he pleased, and took 
no heed of the rest, the result of their work would be 
of little account. The master-builder must be at his 
post, skilful to direct, and quick to act. 

So it is with our bodies. The wonderful agency 
which directs and governs every organ of the body is 
the nervous system. 

147. The Nervous System. — The nervous system is 
to the organs of the body what steam is to the engine. 
Shut off the steam, and the rods, wheels, and bands, 
which a moment before were whirling round, at once 
become still and useless. So with the body : any injury 



178 



YOUNG FOLKS PHYSIOLOGY. 



to the nervous system may paralyze some or all of the 
various organs, and at last produce death. 

The nervous system may be compared to nothing so 
aptly as to a complete telegraphic system. The brain 



CEREBRUM- 



MEDULLA 

OBLONGATA- 
CEREBELLUM" 



SPINAL CORD — 




— SPINAL COLUMN 



CUT ENDS OF 
SPINAL NERVES 



-Fig. 59. — Diagram of Brain and Spinal Cord. 

itself is the main office ; and the thousands of nerve- 
fibres, branching off to all parts of the body, are the 
telegraph-wires. Telegraphic despatches are constantly 
being sent to the brain, to inform it of what is going 
on in various parts of the body. The brain, on receiv- 



THE NERVOUS SYSTEM 1 79 

ing the news, at once sends back its commands as to 
what must be done. 

Thus, if we accidentally pick up a hot coal, we drop 
it instantly. A message is sent from the nerves of 
touch in the fingers to the brain ; and, when the brain 
learns that the fingers are being burned, it hurries off 
its orders to the muscles of the fingers to drop the burn- 
ing coal. We might multiply these examples to almost, 
any extent. Thus every effort of the will we make 
originates in the brain, and is carried out under the 
direction of the nervous system. 

1 Now, you must know that the pain is not really in 
any organ, but in the mind itself, because this alone can 
feel. If we strike the " funny bone " (the place where 
the nerve is in an exposed place as it runs over the 
elbow to the fingers), we feel pain in the third and 
fourth fingers. The brain refers the pain to the end of 
the nerve. Thus, after a limb has been amputated, 
any injury to the stump will be referred to the place 
where the nerve once led. 1 

The nervous system consists of two distinct parts : — 
I. The brain, spinal cord, and cerebro-spinal nerves, form- 
ing an unbroken connection between the brain and all 
parts of the body. 



1 " When the current of a battery is applied to the nerves of an arm-stump, the 
irritation is carried to the brain, and referred to all the regions of the lost limb. 
On one occasion a man's shoulder was thus electrized three inches above the point 
where the limb was cut off. For two years he had ceased to be conscious of his 
limb. As the current passed through, the man, ignorant of its possible effects, 
started up, crying, ' Oh, the hand ! the hand ! ' and tried to seize it with the living 
grasp of the sound fingers. No resurrection of the dead could have been more 
startling." — Dr. S. Weir Mitchell. 



i8o 



YOUNG FOLKS PHYSIOLOGY 



2. The sympathetic system, which is connected mainly 
with the organs of digestion, circulation, and respiration. 
148. Nerve Tissue. — Nerve-tissue is the soft, mar- 
row-like substance which forms the principal bulk of 

the brain, the spinal 
cord, and the nerves. In 
the brain the inner part 
is white, and the outer 
layer is a gray or gray- 
ish-pink substance. In 
the spinal cord the in- 
ner part is gray, and the 
outer white. The gray 
is richer in blood-vessels 
than the white. 

All muscular action, 
we have learned, results 
in the oxidation, or 
burning, of the muscles 
themselves. In the 
same way the work of 
the brain causes the 
oxidation, or burning up, 
of its nerve-tissue ; so 
that every thought, 
every sensation, every 
effort of the will, which 
goes from the brain, 
destroys a part of its substance. 

The nerves are really so many portions of the brain 
and spinal cord, extending into every minute part of the 




Fig. 60. — Diagrammatic view of the Brain, 
Spinal Marrow, and Nerves (from behind). 



THE NERVOUS SYSTEM 151 

body. A nerve is a slender silvery-white cord when 
seen by the naked eye. Under the microscope, this 
white part is seen to consist of bundles of delicate little 
fibres. 

149. The Brain. — The brain is the organ of the 
mind ; in other words, it is the seat of the conscious- 
ness, the intellect, the memory, the will, the affections, 
and the emotions. 

This important organ fills the entire cavity of the 
skull, and consists of a number of separate masses of 
nerve-matter abundantly supplied with blood-vessels. 
Each separate mass is the main workshop for some 
special department of the work of the nervous 
system, and has little or no connection with the other 
parts. 

The average weight of the brain is about fifty ounces, 
or about three pounds. 1 A few cases have been noted 
in men of great mental capacity, in which the brain 
weighed sixty-four ounces. Such instances are, how- 
ever, far from common. As a rule, a large brain is the 
sign of a vigorous mind and superior faculties ; and a 
healthy brain, of a sound, healthy mind. 

The three principal masses which compose the brain 
are, (1) the cerebrum, or brain proper; (2) the cerebellum, or 
lesser brain ; (3) the medulla oblongata. 

1 Daniel Webster's brain weighed fifty-three and a half ounces, and Ruloff's — 
a notorious murderer, but in some respects a very learned man — fifty-nine ounces. 
The brain of Cuvier, the celebrated naturalist, weighed sixty-four and a third 
ounces ; and that of Dupuytren, a famous French surgeon, sixty-two and a half 
ounces. The hats of ten gentlemen were tried upon the skull of Robert Burns, 
and the only one of the ten that could cover it was the hat of Thomas Carlyle. 
An idiot's brain rarely exceeds thirty ounces. 



182 



YOUNG FOLKS PHYSIOLOGY 



150. The Cerebrum, or Brain Proper. — The cere- 
brum fills the whole of the upper part of the skull, and 
is nearly seven-eighths of the entire mass. It consists 
of two parts, or halves, almost entirely separated from 
each other by a deep cleft, or fissure, from front to 




Fig. 61. — Under Surface of the Brain. 

back. Each of these halves — or hemispheres, as they 
are called — consists of three portions, or lobes, so that 
the cerebrum is made up of six distinct parts. 

The cerebrum has a peculiar folded-up appearance ; 
its various folds, or convolutions as they are called, 



THE NERVOUS SYSTEM 1 83 

being separated by deep clefts, sometimes nearly an 
inch deep. In this simple way the surface of the 
brain is increased many fold. The interior part of the 
brain is made up of the white nerve-substance just 
spoken of. The gray matter is the outer layer, about 
one-eighth of an inch in thickness, and is spread over 
the white substance like a handkerchief crumpled up. 1 

The active powers of the brain are supposed to re- 
side in this outer layer ; and these powers are great or 
small, according to the number and the extent of the 
folds, or convolutions. In the lower animals the brain 
has no folds ; but as we pass to animals of a higher grade, 
the folds begin to appear. 

151. The Cerebellum, or Lesser Brain. — The 
cerebellum, or little brain, lies beneath the back part of 
the brain proper, from which it is separated by a fold 
of the dura mater. It is made up of two halves, each 
formed of a number of layers of gray and white nerve- 
matter, curiously arranged, resembling somewhat the 
branches of a tiny tree. 

The functions of the cerebellum are not yet certainly 
known. It is supposed to exercise an influence over 
the muscles of the body, in regulating their move- 
ments. 



1 The brain is enclosed within three distinct layers, called its membranes, — 
the dura mater (" hard mother "), the arachnoid (like a spider's web), and the 
pia mater (" delicate mother "). 

The dura mater is the tough membrane which lines the inner surface of the 
skull, and forms a loose outer covering for the brain. The middle layer, called 
the arachnoid, secretes a fluid which keeps the inner surface moist. The pia 
mater is a very delicate membrane which dips down between and lines the folds of 
the cerebrum, rich in blood-vessels which nourish the brain. 



184 YOUNG FOLKS' PHYSIOLOGY 

152. The Medulla Oblongata. — The medulla oblongata 
is the thick upper part of the spinal cord which is held 
within the cavity of the skull. It is just under the 
little brain, and makes the connecting link between the 
brain and the spinal cord. It is a small affair, only an 
inch and a half long ; but it is a highly important part 
of the brain, since from it arise the nerves which 
regulate breathing, swallowing, the heart's action, and 
so on. 

The seat of sensation is believed to be lodged in the 
upper part of the medulla oblongata. It has also con- 
trol over the action of the lungs and the heart. If this 
part of the brain be broken or cut, respiration and cir- 
culation will at once cease, causing instant death. 

153. The Cranial Nerves. — From the brain pro- 
ceed twelve pairs of nerves, called cranial nerves. They 
pass out of the skull through little holes in its base, 
and supply the face, certain internal organs, and the 
organs of smell, taste, hearing, and sight. These cra- 
nial nerves are of three kinds, — sensory, motor, and 
mixed ; i.e., combining both. 

The tenth pair is called the "wandering nerve." 2 
This is perhaps the most important nerve in the body. 
It supplies the larynx, the lungs, the heart, the stom- 
ach, and the liver. It is partly motor and partly sen- 
sory. 

154. The Spinal Cord. — The spinal cord, or marrow, 
is a cylinder of soft nerve-tissue, extending from the 
base of the skull to the region of the loins, where it 
tapers into little threads. It is a continuation of the 

1 Pneumogastric. 



THE NERVOUS SYSTEM 



185 



medulla oblongata, and its average length is about eigh- 
teen inches. 

Like the brain, the spinal cord consists of the two 
kinds of nerve-matter, — white and gray : but their posi- 
tion is reversed ; the gray being in the inside, and the 
white outside. 

The spinal cord receives impressions from various 
parts of the body by means of its sensory nerves, and 




Fig. 62. — Upper Surface of Brain, showing the Convolutions and its Double Structure. 



carries them to the brain, where they excite sensation, 
or consciousness. 

Again, it sends out, by means of its motor nerves, 
the commands of the brain to the voluntary muscles. 



1 86 YOUNG folks' physiology 

155. Reflex Action of the Cord and Brain. — The 

spinal cord is not merely a bundle of nerve-fibres for 
carrying messages to and from the brain. It has a cer- 
tain power of its own. It acts as a kind of independent 
centre, receiving messages, or sensations, from certain 
parts of the body by means of its sensory nerves, and 
on its own authority sending back orders to the muscles 




Fig. 63. — Vertical Section of the Brain. 

by its motor nerves, without waiting to consult the 
brain. 

This is what it known as reflex action. 

If one is asleep, and the feet are gently tickled, the 
legs will be moved out of the way without the sleeper 
necessarily being awakened. When the spine is broken 
by an injury, causing pressure upon the cord, then all 
sensation and motion are lost in the paralyzed limbs. 
But if these paralyzed limbs are irritated, as by prick- 



THE NERVOUS SYSTEM 1 87 

ing the soles of the feet, then the legs kick out vigor- 
ously. The injured person does not feel the pricking, 
and can exercise no control over the kicking legs. 
There is here no conscious action whatever. 

This unconscious action is the result of reflex action of 
the spinal cord. It is called reflex because the impres- 
sion does not go to the brain, but is " reflected," mean- 
ing "to turn back again," to the seat of injury, from the 
sensory nerves through the motor nerves. 

156. Importance of Reflex Action. — We rarely stop 
to think how important reflex action is to our health, 
comfort, and safety. Because we are able to do hun- 



Brain 





Muscles 



Fig. 64. — Diagrams showing the mechanism of a simple reflex action : i, surface, say of 
mucous membrane ; 2, muscle ; A, sensory nerve ; B, reflex centre ; C, motor nerve. 

dreds of things every day without any effort of the will, 
we are apt to forget its importance. In fact, the greater 
part of nerve-power expended in the body goes to pro- 
duce these numberless reflex actions. We are not so 
independent as one would at first think. Ten thousand 
acts take place which tend to govern and preserve our 
health. We have as little control over them as we have 
over the stars above us. 

We have already been told of a few reflex acts. Let 
us call to mind a few more familiar illustrations. If our 
feet slip on the ice, without the effort of the will the 



1 88 YOUNG folks' physiology 

body tends to recover itself. The mind does not always 
act, at least in the ordinary way, to pull the fingers away 
when they touch a hot stove. We try to brush the flies 
away when we are asleep. By an effort of the will, we 
can stop our breath for a moment or two : but soon the 
call for air is imperative ; and the order must be obeyed, 
whether we will or no. The great work of digestion is 
going on day after day, but we have no control over its 
complicated movements. 

By this wonderful provision of nature the " think-cen- 
tres " are relieved of a vast amount of work. If we were 
forced to use our will-power at every step in the process 
of digestion, the brain would be put to a severe strain. 
We could not eat, and then quietly go about our busi- 
ness. If we had to plan and will every heart-beat, we 
should soon be ready to give up the struggle for life. 

If we had to exert our will every time we breathed in 
or out, we would soon get tired of it, and long to die. We 
could never sleep ; for the brain would have to be on 
the alert to decide if it were time for the next heart-beat, 
the next inspiration, and the proper time for each diges- 
tive fluid to flow. 

157. The Spinal Nerves. — From the spinal cord 
thirty-one pairs of spinal nerves proceed to the trunk and 
limbs. 

They pass out on each side of the spinal canal through 
small holes in the sides of the backbone. Each of these 
spinal nerves has two roots, — one going from the front 
part, and the other from the back part, of the cord. 
These two roots unite, and run side by side, forming 
one silvery thread as they pass out from the backbone. 



THE NERVOUS SYSTEM 1 89 

The root which goes from the front, or anterior, part 
of the spinal cord, is the motor nerve, and controls the 
muscles of the body. 

The one which comes from the back, or posterior, 
part of the cord, is the sensory nerve, and carries sensa- 
tions from the various parts of the body to the spinal 
cord. 

As each nerve-trunk leaves the backbone, it subdivides, 
and sends off branches into various parts of the body. If 
any one of these nerves is cut or injured as it leaves the 
backbone, the power of feeling and movement ceases in 
all those parts to which it is distributed ; that is, those 
parts of the body are paralyzed. 1 The case is practi- 
cally the same as cutting a telegraph-wire, and thus stop- 
ping the passage of the electric current. To a certain 
extent this is the case when our leg or arm "goes to 
sleep." The fact is, some of the nerves have been 
pressed upon, and their action is stopped for the time 
being. Remove the pressure, and the nerves regain 
their power. 9 

158. The Sympathetic System of Nerves. — Besides 
the system of nerves just described, there is another 

1 A very important and interesting point to notice, is that, as the motor nerve- 
fibres leave the brain, they cross over from one side of the spinal cord to the 
other. The sensory nerve-fibres cross in the same way soon after entering it. 
Thus, the right half of the brain governs the left half of the body, and the left half 
of the brain controls the right side of the body. A blow on either side of the brain 
may therefore produce paralysis of the opposite side of the body. Thus, if we see 
a person with left side paralyzed, we know that the seat of injury is on the right 
side of the brain. 

2 Imagine a telegraph-cable of delicate India-rubber tubes filled with mercury ; 
a squeeze would interrupt the continuity of the cable without destroying its phys- 
ical continuity. Remove the pressure, and the current would pass along the 
cable as usual. 



9 o 



YOUNG FOLKS PHYSIOLOGY 



set of nerves, known as the sympathetic neirous system. 1 

It consists of a double chain of nerve-knots, or gan- 
glia, connected by nervous cords running down in front 
and on each side of the backbone. This chain of 
nerves is not shut up within the bony tube formed 
by the skull and spine. The knots of nerves are con- 
nected with each other, and with the sensory roots of 
the spinal nerves, by a network of gray nerve-tissue. 

From these knots, nerves go to all the internal 
viscera, forming a complete system by themselves, and 




Fig. 65. — Section of Spinal Cord, with Roots of Spinal Nerves. Front view. 

acting almost independently of the cerebro-spinal sys- 
tem. A close network of the sympathetic nerves is 
spread round the muscles of the heart, the lungs, the 
stomach, and the intestines, as well as round the walls 
of the minute arteries and capillaries. 

Compared with the cerebro-spinal set of nerves, the 
sympathetic nerves are very slow to act. A blush 
steals slowly up to the roots of the hair. If we go 
from the dark into a strong light, we are blinded; the 

1 The name "sympathetic" is given to this part of the nervous system, 
because it was thought that, through its agency, distant organs have sympathy 
with one another's afflictions. Thus, for example, severe pain in any part of 
the body will cause some sensitive persons to be sick at the stomach. 



THE NERVOUS SYSTEM 



191 



An impression is made 



pupil is too large to endure it 
on the sympathetic 
nerves, which cause 
the pupil to contract 
slowly while we are 
shading our eyes. 

159. The Health 
of the Nervous Sys- 
tem. — It is not nec- 
essary to discuss in 
detail the health of 
the nervous system, 
as we have done with 
the other parts of the 
body. The health of 
every tissue and of 
every organ of the 
body is dependent 
upon, and woven in- 
to, the welfare of the 
nervous system. 1 

1 "Asa king sits high above 
his subjects upon his throne, 
and from it speaks behests that 
all obey, so from the throne of 
the brain-cells is all the kingdom 
of a man directed, controlled, 
and influenced. For this occu- 
pant, the eyes watch, the ears 
hear, the tongue tastes, the nos- 
trils smell, the skin feels. For 
it, language is exhausted of its 
treasures, and life of its expe- 
rience; locomotion is accom- Fig. 66. - The Great Sympathetic Nerve, 
plished, and quiet insured. When it wills, body and spirit are goaded like over^ 
driven horses. When it allows, rest and sleep may come for recuperation. In 
short, the slightest penetration may not fail to perceive that all other parts obey 
this part, and are but ministers to its necessities." — Odd Hours of a Physician. 




I92 YOUNG FOLKS PHYSIOLOGY 

A blow on the head often causes vomiting. If a tiny 
blood-vessel in the brain is broken, and forms a little 
clot as large as a pea, a paralysis of one side may be 
produced by its pressure on the delicate brain-tissue. 
An overloaded stomach may make the brain dull and 
stupid for some time. Ill-digestion may change the 
disposition, and make one cross, morose, and ugly- 
The loss of sleep may cause exquisite suffering. 

In early English history, people who were con- 
demned to death, by being prevented from sleeping, 
always died raving maniacs. Those who are starved 
to death become insane. The brain is not nourished, 
and they cannot sleep. A blow on the head, and cer- 
tain diseases, may produce a profound and mysterious 
effect upon the nervous system. 

On the other hand, severe accidents to the brain may 
not produce serious results. 1 

Like any other organ, the brain may be strengthened 
and increased in its power by use and education. Im- 
pressions made upon the mind in early life are more 
readily received and more completely retained than 
those which are made when the growth of the brain is 
far advanced. For this reason, education should be 

1 A pointed iron bar, three and a half feet long and one inch and a quarter in 
diameter, was driven by the premature blasting of a rock completely through the 
side of the head of a man who was present. It entered below the temple, and 
made its exit at the top of the forehead, just about the middle line. The man 
was at first stunned, and lay in a delirious, semi-stupefied state for about three 
weeks. At the end of sixteen months, however, he was in perfect health, with the 
wounds healed and with the mental and bodily functions unimpaired, except that 
the sight was lost in the eye of the injured side. He died nearly thirteen years 
after the accident. The iron bar and the skull may be seen at the Museum of the 
Harvard Medical College, in Boston. 



THE NERVOUS SYSTEM I93 

begun early in life. It is an object for which most 
parents are willing to work hard, and exercise much 
self-denial, to accomplish. 

160. Abuse of the Nervous System. — Just as the 
stomach may be overworked, and fail after a time to 
digest food properly ; and as muscles are exhausted by 
over-exertion, — so may the nervous system, especially 
the brain, be overtaxed. 

Mental work is rarely hurtful to a healthy person 
who takes good care of himself. It is not so much the 
severe mental toil, as it is worry, that makes the 
mental wreck. It is not study, but fretting, that 
causes the student to break down in his studies. It is 
the wear and tear of the nervous system in the fierce 
struggle for wealth and position, that makes an old 
man out of a young one before he is forty. Let a child 
have plenty of nutritious food properly given, plenty of 
sound sleep, enough of suitable clothing, and a calm 
and wise oversight at home, and he will rarely be in- 
jured by too much study. 

It is fretting about passing examinations, worrying 
about promotions, and other baneful influences which 
have become attached to our educational system like 
barnacles to a stately ship, that make the delicate, 
sensitive child cross, peevish, and sickly, and lay the 
foundation for years of ill-health. 

Every part of the nervous system is busily at work 
doing its allotted duty. The vast sympathetic system, 
which lies at the very foundation of our nutrition, is 
severely taxed to do its work properly. Now, let a 
person fret and worry day after day over real or fancied 



194 



YOUNG FOLKS PHYSIOLOGY 



troubles, abuse his digestive organs by too much or too 
little food, go without proper sleep, turn night into day, 
try to prop up his flagging energies with more or less 




Fig. 67. —Superficial Nerves on the right side of the Neck and Head. 

of alcoholic liquors, and the strain on the nervous 
system will make a physical and mental wreck. 

Like a spendthrift, who lavishly spends his principal, 



THE NERVOUS SYSTEM. 195 

and persists in calling it his income ; so is a man, who 
is indulging in all these forms of dissipation, really 
exhausting the limited amount of nervous force at his 
command. Unhealthful and injurious habits, whether 
in the important or comparatively trifling matters of 
daily living, are drafts drawn on the future, which must 
be met at no distant day with all the attendant perils 
of physical or mental bankruptcy. 

All forms of nervous gratification that pander to the 
lower tastes, as too much reading of sensational litera- 
ture, frequent attendance at low theatrical performances, 
and an over-indulgence in gross pleasures of every kind, 
cause a great waste of nervous tissue, and may in time 
sap the foundation of health and happiness and leave 
its victim at last a wreck of his former self. 

161. Sleep. — Sleep is necessary to life and health. 
In our waking-hours, rest is obtained only at short in- 
tervals. The muscles and nerves, the brain in particu- 
lar, are in full activity when we are awake. Repair 
goes on every moment, whether we are awake or asleep ; 
but during the waking-hours the waste of the tissues is 
in excess of the repair, while during sleep the repair 
exceeds the waste. Hence the good mother Nature, at 
regular intervals, causes all parts of the bodily machin- 
ery to be run at their lowest point. In other words, 
we are put to sleep. 1 

To be sure, the heart beats, the lungs take in air, 
and the stomach digests its food ; but these great 

1 The great classic writers of all time have symbolized sleep under all kinds of 
fanciful expressions. Shakespeare alludes to sleep as " the golden dew," " our 
foster-nurse of nature," " nature's soft nurse," " death's counterfeit," " the death 
of each day's life," " great nature's second course," " chief nourisher in life's 
feast." 



I96 YOUNG FOLKS' PHYSIOLOGY 

organic processes are carried on at their lowest point. 
The vital organs rest because they are worked at 
the lowest rate that will keep us alive. The eye, the 
ear, the brain, and the nerves, are at rest by darkness, 
silence, and unconsciousness. The tired muscle regains 
its vigor, and the exhausted brain is refreshed. 

Sleep is more or less sound according to circum- 
stances. Fatigue, if not too great, aids it ; while idle- 
ness lessens it. Some kinds of food, as tea and coffee, 
may prevent it. Anxious thought and pain, and even 
anticipated pleasure, may prevent it. Just as sleep is 
sound, the body and mind are refreshed. 

The best time for sleep is at night. The soundest 
and best sleep is obtained during its silence and dark- 
ness. People who are forced to work nights, and to 
sleep during the day, have a strained and wearied look, 
which is easily recognized by the trained eye. 

The amount of sleep depends upon our- occupation 
and our temperament. Some require little sleep, while 
others need a great deal. Eight hours of sound sleep 
for a grown man or woman, and more for children and 
old people, is about the average amount required. 
Children naturally need more sleep, because their 
bodies need more rest during the period of growth. 
Hence the infant sleeps most of the time, if well, and 
properly cared for. 

Children should always be put to bed early, and 
allowed to sleep in the morning until they awake of 
themselves. During hot weather, the active child 
should be undressed, bathed, and put to bed in the 
middle of the day for a good nap. Do not go to bed 



THE NERVOUS SYSTEM I97 

with the brain excited or too active. Read some 
pleasant book, laugh, talk, sing, take a brisk walk, or 
otherwise indulge in a little recreation, for half an hour 
or so before going to bed. 

162. Narcotics. — One of the most fruitful sources 
of injury to the nervous system is the use of alcoholic 
drinks, tobacco, opium, and other narcotics. It is be- 
cause of their deadening and paralyzing effect upon the 
nerves that they are called narcotics, or nerve poisoners. 

As we have already seen, a little of any alcoholic 
drinks has the power to create an inclination to take 
them again. Yielding once, they beget an itching de- 
sire to repeat the action. This unhealthy craving may 
pass away, but oftener grows fierce by what it feeds on. 
A man is no longer master of himself, but is the victim 
of a relentless craving for what may sooner or later 
destroy him. It is almost impossible for him to free 
himself from the invisible chains of his baneful habit. 

163. General Effect of Alcohol upon the Nervous 
System. — The real substance of the nerves, the great 
nerve-centres, and the brain, is made up of nerve-pulp, 
the softest and most delicate matter in the body. A 
rude touch will crush and destroy it. It is very rich in 
blood-vessels, which bring blood to renew and nourish 
it, and also to carry away the waste. 

This ceaseless interchange between the blood and the 
nerve-pulp maintains the vital action and power of the 
nervous system. No other part of the living body is so 
sensitive to the presence of alcohol as this delicate 
nerve-pulp. It has much water in it, to keep it in a moist 
and workable condition, but alcohol rapidly takes to 



I98 YOUNG FOLKS' PHYSIOLOGY 

itself the water of the nerve-pulp, thus causing injuri- 
ous changes in the nerve-substance itself in proportion 
to the amount of the narcotic taken. 

Again, when alcohol is once taken up by the nerve- 
tissue, it does not easily escape. In other words, this 
unnatural agent is shut up and imprisoned in the nerve- 
structure, and is only got rid of by a gradual and slow 
process. For these two reasons, therefore, the nerve- 
tissue is peculiarly subject to the injurious effect of 
alcoholic liquors in whatever quantity taken. 

164. Alcoholic Liquors and the Nervous System. — 
The first symptom showing that the nerves are dis- 
turbed by alcohol is the quickened action of the heart, 
and with it the dilatation of the blood-vessels. The 
face is flushed, and there is a warm glow all over the 
bodv, because the nerves which control the action of 
the heart, and those that regulate the size of the blood- 
vessels, are paralyzed by the alcohol. 

The tiny blood-vessels of the brain are overcharged, 
the brain becomes more active, thoughts flow more 
rapidly, and the speech becomes more fluent ; but this 
activity is only an unhealthy excitement. The power of 
right thinking is diminished, and the fluent speech is 
usually lacking in good sense. The use of alcohol, even 
in what is called moderate quantities, in the lighter 
liquors, such as beer, wine, and cider, tends through its 
action on the brain, to weaken the judgment and to 
blunt the moral sense. 

The nerve-pulp of the higher, or controlling, part 
of the brain is next brought within the grasp of this 
deadly alcoholic influence, and the faculties of the mind 



THE NERVOUS SYSTEM 1 99 

are still more impaired. Reason is off duty ; and the 
lower, or animal, impulses begin to manifest themselves. 
First, the control of judgment and the will 1 disappears ; 
and the emotional, the impulsive, and the purely in- 
stinctive part of our nature is laid bare. It is a fact of 
common observation that alcohol is one of the greatest 
criminal forces in the world, and as we come to under- 
stand its action on the brain we see why this is so. 

If still more alcohol is taken, those actions of life 
which are under the direct control of the spinal cord 
become disturbed. The power over some of the mus- 
cles is lost, and the energy of the whole muscular sys- 
tem is lessened. The muscles of the lower lip and the 
legs are the first to feel this unnatural torpor. The 
speech is thick, and the gait uncertain. Trembling, 
faintness, and vomiting are more or less frequent. 

In the last stage of all, the paralysis, of the nerve- 
centres and of the brain is carried to its full extent. 
All the inlets of the senses are closed, all conscious- 
ness and sensation are lost, and all power over the vol- 
untary movements is gone. The heart still beats, and 
the Hood circulates, and the breathing still goes on ; 
but these are the sole remnants of vitality, the slender 
threads by which a hold is retained upon life. 

165. The Final Result. — After a time, the contin- 
uous use of alcohol steadily weakens the self-control of 
its hapless victim, and at last makes him an utter slave to 



1 " Under the influence of alcohol, the weakening of the will becomes excessive. 
The extravagances, violences, and crimes committed in this state are innumerable." 
— Dr. J. Ribot. 



20O YOUNG FOLKS PHYSIOLOGY 

his lower nature. 1 The craving for ardent spirit be- 
comes well-nigh irresistible. Self-respect, honor, con- 
science, everything, is sacrificed to get fresh fuel for the 
alcoholic fire which is burning up its victim. The road 
is now straight which leads to some private " retreat/' 
or even the insane-asylum. 

The disease known as delirium tremens, meaning a 
trembling madness, is a terrible instance of the effect 
which alcoholic liquors may exercise over the nerve- 
centres. It is marked by muscular tremors, a low tem- 
perature, cold and clammy skin, persistent wakefulness, 
muttering talk, then the wildest delirium, with all the 
horrors of hideous delusions which imagination can 
possibly conceive. 2 

These extreme instances of the breaking-up of the 
nervous system are found in our insane-asylums, — men 
and women who have lost every trace of humanity ; 
hopeless, helpless, doomed to a living death until they 
cease to be. 

The insanity of a large number of the inmates of 
nearly all insane-asylums is due to the use of alcoholic 
liquors. In each case the first glass was the first step 
toward this fate. 

166. The Inherited Craving for Alcohol. — The crav- 
ing for alcohol may be inherited by its victim's innocent 

1 '•' O, that men should put an enemy in their mouths, to steal away their 
brains ! that we should, with joy, revel, pleasure, and applause, transform ourselves 
into beasts ! " — Othello, Act ii. Scene 3. 

2 u The victim almost always apprehends some direful calamity ; he imagines 
his bed to be covered with loathsome reptiles ; he sees the walls of his apartment 
crowded with foul spectres ; and he imagines his friends and attendants to be fiends, 
come to drag him down to a fiery abyss beneath." — W. B. Carpenter, M.D. 



THE NERVOUS SYSTEM 201 

children. Just as we may inherit from our parents 
mental and physical vigor or weakness, our features, 
and even moral traits, so it is possible to inherit a thirst 
for alcoholic drink. This inherited curse of strong 
drink has caused many a good family to " run out," 
and leave the children and grandchildren pitiable wrecks 
of humanity. 

Again, the children of parents whose brains are in- 
jured by alcohol, are more prone than others to mental 
disorders, and to those widely varied diseases which, for 
lack of a better name, we vaguely call " nervous." 

Weak moral natures, and a tendency to lying and 
deceit and other forms of wrong-doing, are only a few 
of many baneful defects which children may inherit 
from drinking-parents. 1 

167. Tobacco. — Tobacco, whether snuffed, chewed, 
or smoked, is a narcotic and a poison. Its injurious 
effects are due to its active principle called nicotine, 
which is of itself a narcotic poison. 

Tobacco is hurtful to young people, and by no means 
free of harm to adults. It produces an artificial ex- 
haustion, as it were, of the nerve-centres. The to- 



1 This point has been very tersely put by a sagacious physician, the late Dr. 
Willai-d Parker of New York. He says : " There is a marked tendency in nature 
to transmit all diseased conditions. Thus the children of consumptive parents are 
apt to be consumptive. But, of all agents, alcohol is the most potent in establish- 
ing a heredity that exhibits itself in the destruction of mind and body. There is 
not only a propensity transmitted, but an actual disease of the nervous system." 

"The appetite for strong 1 drink is frequently transmitted from parents to the 
children, just as other traits of the mind or body. Sometimes it develops early, 
sometimes late in life. As a rule this hereditary propensity shows itself at an 
early age, and is apt to be intensified at the age of maturity." — Dr. James C. 
Wilson, in Pepper's System of Medicine, vol. v. p. 634. 



202 YOUNG FOLKS PHYSIOLOGY 

bacco habit once acquired generally leads to continual 
and increasing use. 

Thus, after a time, tobacco produces functional de- 
rangement of the nervous system, palpitation of the 
heart, certain forms of dyspepsia, and more or less 
irritation of the throat and lungs. 

Sometimes, after long smoking, a sudden sensation 
of dizziness, with a momentary loss of consciousness, 
is experienced. At other times, if walking, there is a 
sudden sensation of falling forward, or as if the feet 
were touching cotton-wool. While the stomach is 
empty, protracted smoking will often produce a feeling 
of nausea, accompanied with a headache. 1 

The brain will often become affected. The ideas 
lack clearness of outline. The will-power may be 
weakened, and it may be an effort to do the routine 
duties of every-day life. The old tobacco-user is often 
cross, irritable, and liable to outbursts of passion. The 
memory is also quite often impaired for the same rea- 
son. The narcotic principle, the deadly nicotine, has 
become soaked into the delicate nerve-pulp retarding 
its nutrition. The nerve-centres are no longer able to 
hoard up their usual amount of vital energy. Hence 
arise the many and various nervous symptoms due to 
the poisonous effect of tobacco. 

!The external application of tobacco to chafed surfaces, and even to the 
healthy skin, will occasion severe, and sometimes fatal, results. A tea made of 
tobacco, and applied to the skin, has caused death in three hours. A tobacco 
enema has resulted fatally within a few minutes. Smoking a large quantity of 
tobacco at one time has been known to produce violent, and even fatal, effects. 
Nicotine is one of the most rapidly fatal poisons known. It rivals prussic acid 
in this respect. It takes about one minute for a single drop of nicotine to kill a 
full-grown cat. A single drop has killed a rabbit in three minutes. 



THE NERVOUS SYSTEM 203 

168. Effects of Tobacco upon Young People. — To- 
bacco, in any form, has a peculiarly injurious effect 
upon young and growing persons. It not only stunts 
their growth, but produces a weakened state of the 
system, which tends greatly to impair muscular and 
mental activity. The profound effect that tobacco has 
upon the nervous system, after the first trial of smok- 
ing or chewing, is matter of familiar experience. Even 
after the system gets used to the narcotic, young peo- 
ple continue to suffer oftentimes from nausea, dizzi- 
ness, headache, muscular trembling, loss of appetite, 
and general weakness. 



Evil Effects of Tobacco. — " Tobacco reduces the intellectual power 
of a boy. It does this either by opposing mental application and effort, 
or else by producing deterioration of the intellect, probably both to a 
greater or less degree. — Dr. E. O. Otis, in Boston Medical and Surgical 
Journal. 

" It is our deliberate opinion that the unsatisfactory recitations and 
consequent failures at final examination, so injurious to the interests of 
this establishment, are to be attributed, in great measure, to nervous 
derangement caused by the common use of tobacco by the students. It 
becomes our duty to recommend some stringent measures to correct 
this practice." — Medical Report on the Use of Tobacco by the Cadets at the 
U. S. Naval Academy. 

The evils of tobacco are intensified a hundred fold upon the young. 
Here it is unqualifiedly and uniformly injurious. It stunts the growth, 
poisons the heart, impairs the mental powers, and cripples the individual 
in every way. Not that it does all this to every youth, but it may be 
safely asserted that no boy of twelve or fourteen can begin the practice 
of smoking without becoming physically or mentally injured by the time 
he is twenty-one. 

" Sewer-gas is bad enough, but a boy had better learn his Latin over a 
man-trap than get the habit of smoking cigarettes." — New York Medi- 
cal Record. 



204 YOUNG FOLKS PHYSIOLOGY 

The use of cigarettes by young persons cannot be 
too severely condemned. They are made of the mean- 
est materials, and often " doctored" with refuse sub- 
stances, and even forms of opium, in order to give 
some bulk and " tone " to the originally cheap and filthy 
material. Cigarettes are so common and so cheap, that 
their use by thousands of young persons has become a 
serious matter. 

Here is one bit of advice for you to remember all 
the days of your life : Do not smoke or chew tobacco 
if you wish to keep strong and well, and to succeed in 
life. 

169. The Use of Tobacco from a Moral Point of 
View. — The effect of tobacco on the moral nature 
often shows itself in a selfish disregard for the rights 
of others. The smoker has no right to make the air 
about him unfit for others to breathe, with his tobacco 
smoke ; he has no right to puff his smoke into the faces 
of people on the streets, or to thus pollute the air of 
public places which others are obliged to share with 
him. 

The fact that he does this knowing that to many 
people the smoke of tobacco is offensive, and that some 
are even made sick by it, shows his lack of refinement 
as well as moral sense. Other evidences of the same 
character are the filthy habits of spitting on sidewalks, 
floors, stoves, and other objects which characterize 
both smokers and chewers of tobacco and disgust all 
cleanly people. 

It is no mark of friendship or courtesy to offer a 
person a cigar or cigarette, for it is virtually asking 



THE NERVOUS SYSTEM 205 

him to take what will be to him more or less of an 
injury instead of a benefit. 

170. Opium. — Opium, one of the most power- 
ful poisons, is the dried juice of the white poppy. 
It has the power of relieving pain, and producing a 
kind of sleep. Morphine is a white crystalline pow- 
der made from opium. Laudanum is made by mace- 
rating powdered opium in dilute alcohol. Paregoric 
is a weak tincture of opium combined with camphor 
and aromatics. Dover's powder is made of opium and 
ipecac. 

The various forms of opium are very generally used in 
patent medicines. They form the " soothing " basis of 
liniments, "cough-killers," "soothing-sirups," stomach- 
bitters, cholera-mixtures, and countless other prepa- 
rations, which people are eager to buy, hoping to get 
relief from some real or fancied disease. 

Thousands of tons of opium are smoked and chewed, 
like tobacco, in distant parts of the world, especially in 
China, causing great degradation and misery among the 
people. This habitual use of opium is, however, a 
common vice everywhere. Over half a million pounds 
were imported into this country in one year recently, 
and a large proportion of this enormous quantity, it is 
claimed, was consumed by " opium-eaters." 

Opium leaves its after-effects in dryness of the 
mouth, thirst, nausea, constipation, and a dull head- 
ache. In large doses, there are giddiness and stupor. 
A person becomes motionless and insensible to outward 
impressions ; he lies quite still, with the eyes shut, and 
the pupils contracted ; and the whole expression of the 
countenance is that of deep repose. As the poisoning 



206 

advances, the features become ghastly, the pulse feeble, 
and the muscles greatly relaxed ; and, unless help is 
procured, death speedily ensues. If the person re- 
covers, the insensibility is succeeded by sleep for one 
or two days, followed by nausea, vomiting, and loathing 
of food. 

Eaten or smoked habitually to satisfy a craving for 
it, opium makes a living death for its victim. A person 
may begin in the most innocent way to use a little 
opium to relieve pain : little by little, the meshes of 
this fascinating narcotic are woven about him. The 
opium relieves the suffering, but the worst of it is, a 
person cannot leave off its use without the greatest 
effort. A craving is stimulated which no one can real- 
ize unless he has once been within the destructive toils 
of this .drug. It is untold misery to quit it, and sure 
death to keep on using it. 

This habit of taking opium completely changes its 
victim. A man, once upright and honest, will lie, cheat, 
defraud, or even commit murder, to satisfy his awful 
craving for this baneful drug. Promises and resolu- 
tions to stop its use may be honestly made, but are no 
more binding than ropes of sand. He seems to be 
worked upon by some powerful charm. 

The deepest melancholy settles on the opium-eater ; 
and life, once full of joy and happiness, is indeed a 
heavy burden. He would gladly commit suicide, but 
he cannot summon the will-power to do the deed. 

Meanwhile all the vital organs are slowly and surely 
losing the power to do their work. The fat disappears ; 
the muscles grow weaker; the stomach and bowels fail 



THE NERVOUS SYSTEM 20? 

to act ; the skin becomes dry, yellow, and shrivelled, 
like yellow-leather parchment ; and death at last puts 
an end to his misery. 

171. Practical Points about Opium. — The so-called 
soothing-sirups, cough and cholera mixtures are often 
given to infants and young children. All of them con- 
tain more or less of some form of opium. 1 The child 
is simply drugged, and not cured, however " soothing" 
the effect may be. The only safe rule is, never to put 
opium on the list of home remedies. 

A good physician often hesitates to use this drug 
with children, for he knows how dangerous and uncer- 
tain the effect may be. The practice of rubbing the 
gums of teething-children with paregoric, putting lauda- 
num into a child's aching tooth or ear, giving either 
preparation for "summer complaints," and other house- 
hold ways of using opium, is dangerous. 

Nine times out of ten, some simple and safe remedy 
will answer every purpose. Never rub any form of 
opium powder upon any abraded surface to relieve 
pain. It is rapidly taken up by the blood. " Dover's 
powder" is not a home remedy: a single grain has 
killed an infant. Remember that laudanum that has 
been kept in the cupboard for a long time may become 
stronger, on account of the evaporation of the alcohol. 

Remember that children as a rule, and many grown- 
up people too, are very susceptible to the action of 
opium. It is well known that a child may be drugged 
by the milk of a nurse who has taken opium. Young 

1 " It is very certain that many infants annually perish from this single cause." 
— Reese's Manual of Toxicology. 



208 YOUNG FOLKS' PHYSIOLOGY ' 

boys have been made stupid, getting even the "pin- 
hole pupil," : by smoking cigarettes that have been doc- 
tored with opium. Poultices saturated with laudanum 
are by no means safe. They are especially dangerous 
in the case of infants. 

The only safe rule, therefore, is, to let everything 
that has opium in it severely alone. Above all things, 
do not give to others, especially children, any opium- 
mixture that has been prescribed or used by some 
one else. It is better to endure pain. 

172. Chloral. — Chloral is a powerful drug, capable, 
in small doses, of producing quiet sleep. This action 
is probably due to its direct effect upon the brain. In 
fall doses it depresses the action of the nerve-centres 
of the brain and spinal cord. In large doses, there is 
paralysis of the nerve-centres, causing death. Because 
chloral is known to induce sleep, especially in those 
who suffer from excessive mental strain, or from 
anxiety, or other like cause, it has come, of late years, 
to be often used without a physician's advice. 

Like all narcotics, the dose must be steadily increased 
to get the required effect. The " chloral habit" is 
soon formed, and the person becomes a slave to a dan- 
gerous drug. Without it, the chloral-eater cannot 
sleep: with it, his digestion is sadly out of order. He 
suffers from dyspepsia, shortness of breath, and palpi- 
tation of the heart. The habit begets carelessness in 
its use ; and the fatal dose is so uncertain, that chloral- 
eaters often die from an overdose. 

1 One of the physiological effects of opium is to contract the pupil of the 
eye. Hence the name of "pin-hole "is given to the pupil contracted by a large 
dose of any opiate. 



THE NERVOUS SYSTEM. 200, 

The only safe rule is, never to touch so powerful, 
uncertain, and dangerous a drug. It is better to con- 
sult the family physician. 

173. Other Powerful Drugs and Narcotics. — Re- 
garding chloroform, ether, hasheesh or Indian hemp, 
and other narcotics, it may be said, once and for all, that 
they should never be used, even in the smallest doses, 
unless under medical advice. They are dangerous 
agents at all times, and are used with great caution, 
even by physicians. Persons who get into the habit of 
tampering with such powerful drugs run the ever- 
present risk of killing themselves by an overdose. 

Inhaling ether or sniffing chloroform on a handker- 
chief, as a household remedy, to relieve spasms of pain, 
should be always severely condemned. Familiarity 
with these and all other powerful drugs and narcotics 
is sure to beget carelessness on the part of those who 
use them on themselves. 

Since that far-reaching epidemic known as influenza, 
or "la grippe," made such sad havoc in the past few 
years with the lives and health of people all over the 
world, a new class of uncertain but powerful drugs 
has come into extensive use, even in the household. 

They are known by various fanciful and scientific 
names. Let them severely alone. They are too pow- 
erful and uncertain drugs for household use. Remem- 
ber that your family physician will prescribe them only 
with the greatest caution. 



2IO YOUNG FOLKS PHYSIOLOGY 



CHAPTER XII 

THE SPECIAL SENSES 

174. Sensation. — In the preceding chapter we have 
seen that all nerves belong to two classes : — 

1. Motor nerves, which control the action of the mus- 
cles of the body. 

2. Sensory nerves, which carry a variety of impressions 
from all parts of the body to the brain. 

When the brain receives a certain impression by 
means of some sensory nerve, we become conscious of 
a feeling, or sensation. 

Exactly how we become conscious of the thousand 
and one sensations felt by all, is one of the many mys- 
teries connected with the human body. Some sensa- 
tions, such as those of faintness or fatigue, spring up 
within us in some mysterious way, without any appar- 
ent cause. Most sensations, however, are produced by 
some outward agency. 

Thus, if we hear a child cry, or a bird sing, we have 
a sensation of sound. If we are pinched, tickled, or 
struck, we have a sensation corresponding to these acts. 
If we put a piece of sugar on the tongue, hold a rose 
at the nose, or prick the skin with a pin, certain sense- 
organs receive the impressions, and the sensory nerves 
carry them to the brain, where we become conscious of 
a sensation. 

Sensations may be those of pleasure or pain. In- 



THE SPECIAL SENSES 211 

deed, the same agent may be either pleasant or painful, 
according to its degree of intensity. It is pleasant to 
hold out the hands before a glowing fire after a cold 
ride. Hold the hands too closely, and the sensation of 
pleasure is changed in a moment to one of pain. 

All sensations are produced by three distinct organ- 
isms : — 

i. An organ specially adapted to receive the stimulus 
from the outer physical agent. 

2. An incoming, or sensory, nerve to carry the im- 
pression from the sense-organ to the brain. 

3. The brain itself, some part of which converts the 
impression into an actual sensation to the mind. 

Take, for instance, the sense of hearing. The waves 
of sound pass through the air from the outer physical 
agent. The ear is the organ specially adapted to re- 
ceive impressions from it. The nerve of hearing, or 
auditory nerve, forms the connection between this 
organ and the brain, where the consciousness of sensa- 
tion actually takes place. 

175. The Five Special Senses. — There are five 
ways in which the brain becomes acquainted with what 
takes place in the outer world. In other words, there 
are certain sets of nerves which carry special sensations 
to the brain. 

We are said to have five special senses, 1 or " gate- 
ways of knowledge," — touch, taste, smell, hearing, and 
sight. 

1 There is another sense, commonly called the mttscular sense, which enables 
us to judge the weight of different bodies, according to the muscular effort re- 
quired to lift or hold them. This sense becomes so highly developed with use, 
that shopkeepers, and others who sell various articles by weight, will often tell you 
the weight of a body by simply balancing it in their hands. 



212 YOUNG FOLKS PHYSIOLOGY 

176. Touch, or Feeling. — The sense of touch is 
the most widely extended of all the senses, and perhaps 
the simplest. It has its seat in the skin all over the 
body, and in the walls of the mouth and nasal passages. 
By this sense of touch we tell whether a body is hard 
or soft, hot or cold, rough or smooth. We have been 
told in chapter x. about the thousands of tiny hillocks 
called papillcz, which form rows of ridges very thick on 
the tips of the fingers. 

"Now, besides a tiny artery and vein, finer than the 
finest hair, there is in each papilla the end of a sensory 
nerve. Where the sense of touch is most delicate, the 
papilla is found to contain a little oval bulb called the 
touch-corpuscle. All parts of the body do not have 
this sense of touch in an equal degree. 1 It is most 
delicate in the tip of the tongue, the tip of the fingers, 
and the edge of the lips, and least delicate in the middle 
of the back. 

177. Taste. — The tongue is the principal organ of 
taste. It has two coverings, — a deep, sensitive layer, 
and an outer layer. When the stomach is out of order, 
and in certain diseases, this outer layer is covered 
with a whitish or yellowish matter. We generally 
speak of the tongue at such a time as being coated. 

The deep layer is raised up, like the true skin, into 

1 There is no sense so capable of improvement as that of touch. The female 
silk-weavers of Bengal are said to be able to distinguish, by the touch alone, twenty- 
different degrees of fineness in the unwound cocoons, which are sorted accord- 
ingly. 

The sense of touch may be said to belong to every animated being, and is one 
great characteristic of animal life. In many animals the tongue is the instrument 
of touch as well as of taste. Certain animals, in addition to the tongue, have 
special organs of touch, as the whiskers of the cat and rabbit. 



THE SPECIAL SENSES 



213 



EPIGLOTTIS 



PAPILLA 



tiny hillocks, or papillae, which are abundantly supplied 
with delicate nerve-fibres from two great nerve-branches 
leading from the brain. These are the nerves of taste. 

The tip and the back of the 
tongue are supplied with dif- 
ferent nerves. The papillae 
are small, and pointed on the 
tip, and arranged in the form 
of a letter V, with the point 
towards the back. 

Hence it makes a difference 
in the taste, whether we put 
a substance to be tasted on 
the tip or back of the tongue. 
Thus, alum tastes sour on 
the tip, and has a sweetish 
taste on the back part, of 
the tongue. 

In certain animals, these 
last-mentioned papillae are 
very largely developed, and 
give a roughness to the tongue. We have all, no 
doubt, noticed how rough a dog's tongue is. It is this 
which enables the dog to strip off the flesh from a bone 
by simply licking it ; while the lion by the same means 
strips the skin from his victim with one stroke of his 
tongue. 

In this sense, as in the other special senses, the 
nerves receive the impression, and carry it to the brain, 
where it is perceived, and gives rise to the sensation of 
taste. 




Fig. 68. — Upper Surface of the 
Tongue, showing the Papilla?. 



214 YOUNG FOLKS' PHYSIOLOGY 

178. Smell. — The seat of the sense of smell resides 
in the cavities of the nose, into which the nostrils 
open, and which open behind into the pharynx, or the 
back part of the mouth. The walls of the nasal cav- 
ities are lined with a thick, velvety membrane, over 
which the nerves of smell are distributed. This mem- 
brane is kept continually moist by a fluid which it 
secretes. At the beginning of a cold in the head, this 
membrane becomes dry and swollen, and the sense of 
smell is greatly lessened. 

It is in the roof of the nasal cavities that the sense 
of smell is most acute. 1 Hence, when we wish to de- 
tect a faint odor, we sniff up the air sharply. By doing 
so, we cause a rush of air into the higher parts of the 
cavities, where some of the floating particles come into 
contact with the nerves of smell. 

The sense of smell is Nature's sentinel to guard us 
against taking improper food into our stomach, and 
impure air into our lungs. By this same sense, we 
are able to detect delicate and fragrant odors, which 
add much to the comfort of our daily living. 

179. The Sense of Hearing. — We come now to 
a special sense, which does not tell us what is going on 
in the outer world by actual contact, as in touch or 



1 The sense of smell varies very much in different individuals. Among civil- 
ized people, it is rather defective, while in savage races it is most acute. We 
are told that the South-American Indians can detect the approach of a stranger, 
even in a dark night, by their sense of smell, and can also tell whether he is white 
or black. Many animals are more highly endowed with this sense than man. 
Thus, a dog will smell the footsteps of his master amid those of a hundred other 
people, and can trace him for miles, although he has been for hours out of sight. 
Pointers also scent game at a great distance. 



THE SPECIAL SENSES 



215 



taste, nor by particles of matter falling upon the end 
of nerves, as in the sense of smell. In this sense, 
impressions are produced upon nerves by wave-like 
vibrations in the surrounding air. 

This is the sense of hearing, only second in impor- 
tance to the sense of sight. All sounds are produced 
by the vibration of some body in the atmosphere. The 



OLFACTORY NERVE 



BRANCHES OK 
CTORY NERVg" 




INTERIOR OF 
NOSTRIL 



Fig. 69. — Sectional View of the Nose. 

body sends out these vibrations to the surrounding air, 
which carries forward a series of waves in all direc- 
tions. 1 

These air-waves are received, and the impression 

1 We shall understand these air-waves better if we throw a stone into a pool of 
water, and watch the result. We see a series of tiny circular ripples gradually- 
spread themselves over the surface of the water from the spot where the stone 
fell. This exactly represents the waves of sound caused by the vibration of 
bodies in the air. These air-waves travel with wonderful rapidity. The usual 
velocity of sound is about eleven hundred feet a second. 



2l6 YOUNG FOLKS' PHYSIOLOGY 

made by them is sent to the brain, by a special appa- 
ratus, called the organ of hearing. 

The organ of hearing is lodged in the thick inner 
bones forming the base of the skull. The ear, the 
organ of hearing, is far more complicated than any of 
the organs of sense yet described. 

It is divided into three parts, — the outer, the middle, 
and the inner ear. 

180. The Outer Ear. — The outer ear consists of a 
broad plate of gristle, shaped somewhat like a shell, 
commonly called "the ear;" and of a tube about an 
inch long, called the auditory canal. 

This canal is in the solid portion of the temporal 
bone. It is protected by fine hairs, and by a set of 
glands which secrete ear-wax, a bitter substance, which 
serves to moisten the parts, catch particles of dust, and 
keep away small insects. 

The inner end of this canal is closed by a membrane 
stretched tightly across it. It resembles the parchment 
stretched across the end of a drum, and is known as the 
membrane of the drum of the ear. It is thin and elas- 
tic, but may be easily broken by a blow, or by pushing 
anything into the ear. If once broken, this delicate 
membrane cannot be repaired, and deafness results. 

181. The Middle Ear. — The middle ear is a small 
cavity hollowed out in the temporal bone, between the 
membrane of the drum and the inner ear. This cavity 
is the " drum " of the ear. 

The most curious feature of the drum is a string of 
three of the tiniest bones, which stretch across it. 
They are sometimes called the hammer, 1 anvil, 2 and 

1 Malleus. 2 Incus. 



THE SPECIAL SENSES 



217 



stirrup, 1 bones from some fancied resemblance to these 
articles. 

The hammer-bone is fastened by its long handle to 
the membrane of the drum. The round head of the 
hammer-bone fits into the anvil-bone. Next to the 




Fig. 70. — Section showing the different parts of the Ear. 

anvil is the stirrup-bone, which fits into a little oval 
window in the opposite wall of the chamber, or drum. 

In the floor of this chamber is the opening of a pas- 
sage called the eustachian tube. 2 This tube is about an 
inch and a half long, and leads into the throat. It 

1 Stapes (the smallest bone in the human body, being one-eighth of an inch 
long). 

2 Named after Eustachi, a famous Italian anatomist, who died more than 
three hundred years ago, and who first described it. 



2l8 YOUNG FOLKS' PHYSIOLOGY 

allows air from the throat to enter the drum, and serves 
to keep the air on both sides of it at a constant and 
even pressure. 1 To hear perfectly well, this passage 
must be kept open for the air to pass in and out. 

During a severe cold in the head, or a sore throat, 
the lining of the tube may be inflamed and swollen. 
This gives a stuffed feeling and an alteration of sounds 
in the ears. This should not be neglected if it does 
not pass off in a few days. Should it continue, it will 
show that more than ordinary swelling has occurred in 
the tube ; and it will be found that the hearing is 
slightly impaired. Usually, as the cold passes off, this 
peculiar feeling in the ears passes away. 

182. The Inner Ear. — The inner ear is one of the 
most delicate and complex pieces of mechanism in the 
whole body. It is that part of the organ of hearing 
which perceives the impression of sound, and carries 
that impression directly to the brain, where it gives rise 
to the sensation of hearing. It is really a bony case 
filled with a watery fluid, in which float the delicate 
parts of the inner ear. 

The inner ear consists of three distinct portions, — 
the hall-way, 2 the canals, 3 and the snail's shell. 4 It is 
enough to say that these are winding channels and 
spiral tubes hollowed out in the solid bone. The whole 

1 This passage is ordinarily closed ; but when the orifice in the throat is 
opened, as in the act of gaping or swallowing, the air rushes into the cavity of the 
tympanum. Close the mouth, and pinch the nose, and then try to force air 
through the latter. Air is thus forced through the eustachian tube. A distinct 
crackle or clicking sound is noticed, due to the vibration of the membranes, and 
the movements of the little bones of the ear. 

2 Vestibule. 8 Semi-circular canals. 4 Cochlea. 



THE SPECIAL SENSES 



219 



system of passages is known as the "labyrinth." It is 
important to remember, that there is a continuous con- 
nection between all the passages of the inner ear, and 
that all the winding tubes and chambers enclose and 




Fig. 71. — The internal mechanism of the Ear — greatly enlarged. 

protect a delicate bag of membrane of exactly the same 
shape as themselves. 

The auditory nerve, or nerve of hearing, passes from 
the brain, through a little hole in the solid bone of the 
skull, to the inner ear, and is spread out on the lining 
membrane. 

183. How we Hear. — Let us try and understand a few 
of the simplest principles of this wonderful mechanism 
of the ear. A bell is rung, or a gun fired. The vibra- 
tion is communicated to the atmosphere around it, and 
passes away in air-waves from the sounding body, as 



220 YOUNG FOLKS PHYSIOLOGY 

the waves ripple the surface of a pond after a stone has 
been thrown in. 

The air-waves go into the outer ear, and strike upon 
the stretched membrane of the drum, and cause it to 
vibrate. At every vibration of the membrane, the head 
of the hammer-bone strikes upon the anvil-bone, drives 
it forward, and pushes the foot-plate of the stirrup-bone 
in and out of the oval window on the inner wall of the 
chamber. 

The watery fluid in the inner ear washes tiny grains 
of sand against the membranous bag, and so strikes the 
ends of the auditory nerves. These nerves flash the 
impression they have received to the brain. It is in 
the brain itself that the sensation of hearing takes 
place. 

184. Care of the Ear. — The ear is a very delicate 
organ. It is often carelessly and ignorantly tampered 
with, when it should be let alone. It is often neglected 
when skilled treatment is urgently needed. 

The ear-canal should never be rudely or hastily 
washed out, either with a syringe or a wash-rag. The 
utmost gentleness in washing out the ear is all that is 
necessary for cleanliness. Children's ears should never 
be pulled or boxed. 1 Even a slight blow has resulted 
in serious trouble. 

Never use ear-picks, ear-spoons, the end of pencils or 

1 Thus, a " box on the ear," a blow on the ear or head of any kind, or a fall 
may be the direct cause of permanent deafness. Sometimes the deafness is total 
as well as sudden. 

Deafness from concussion, as a tumble down-stairs in childhood, or from a 
severe blow of any kind on the head, may be the foundation of deaf-dumbness, if 
the injury occur before the child has learned to talk. 



THE SPECIAL SENSES 221 

pen-holders, pins, hair-pins, tooth-picks, towel-corners, 
etc., to pick, scratch, or swab out the ear-canal. It is a 
foolish, needless, and dangerous practice. There is 
always risk that the elbow may be jogged in many ways, 
and the pointed instrument pushed through the drum- 
head. 

Let the ear-wax take care of itself. The skin of the 
ear grows outward, and the extra wax and dust will be 
naturally carried out if let alone. Never drop sweet-oil, 
glycerine, and other fluids into the ear, with the idea 
that the ear is cleaner for them. They do no good, and 
often irritate the ear. Never advise or allow any of 
the many nonsensical things so commonly used, to be 
put into the ears to cure deafness. Cotton wads may 
be gently put into the ears to shield them from the 
cold, or may be worn in swimming or diving, to keep 
the water out. Diving into deep water, or bathing in 
the breakers, often injures the ears. 

One should never shout suddenly in a person's ear. 
The ear is not prepared for the shock, and deafness has 
occasionally resulted. If the eustachian tube is closed 
for the time, a sudden explosion, noise of a gun or 
cannon, may burst the drum-head. Soldiers during 
heavy cannonading open the mouth to allow of an equal 
tension of air. 

Flies, bugs, ants, and the like, sometimes crawl into 
the ear. This may cause some pain and fright, and 
perhaps lead to vomiting, and even convulsions with 
children. A lighted lamp put at the entrance of the 
ear will often coax insects to crawl out towards the 
light. The ear may be syringed out with a little 



222 YOUNG FOLKS PHYSIOLOGY 

warm water. Drop in a few drops of molasses or warm 
sweet-oil. 

When the ears run for any cause, it is not best to 
plug them with cotton wads. It only keeps in what 
should come out. Very cold water should never be used 
in the ears or nostrils if it can be helped. Use only 
tepid water. Do not go to sleep with the head on the 
window-sill, or in any position that may expose the ears 
to a draught of cold or damp air. 

185. The Sense of Sight. — Sight, or vision, is a 
wonderful thing when we come to think about it. That 
we have a means by which we can tell what is going on 
in the outside world, is a precious gift. We watch a 
huge balloon from the time it leaves the ground till it 
is a mere black speck in the atmosphere above us. We 
follow the vessel sailing along on the dim horizon, and 
the next instant we are reading the fine print of a news- 
paper. We recognize the form, size, color, and distance 
of thousands of different objects in nature every day of 
our lives. 

This sense is so woven into the countless acts of our 
every-day affairs, that we scarcely appreciate this mar- 
vellous gift, so essential, not only to the simplest mat- 
ters of comfort, but also of prime importance in the 
culture of the mind and the higher forms of pleasure. 

Sight is well held to be the highest and most perfect 
of all the senses. 

186. The Eye. — The eye is the outer instrument of 
sight, and is a most beautiful and ingeniously built 
machine. This little organ, only about an inch in 



THE SPECIAL SENSES 223 

diameter, is in reality one of the greatest wonders in 
nature. 

The eyeball is lodged* in a hollow cone made up of 
seven little bones, with the base pointing outwards and 
forwards. This eye-socket, or orbit, is well protected 
on its edges by the dense and strong bones of the head. 

The eyeball rests in a soft and elastic bed of fat, 
which supports and protects it, and at the same time 
allows it to move in all directions as freely as if it floated 
in a dense fluid. 

187. The Coats of the Eye. — The walls of the eye- 
ball are made up of three distinct coats, or coverings. 1 

The outer covering is the tough coat (sclerotic), which 
is generally spoken of as the "white of the eye." It is 
one of the toughest and strongest membranes in the 
body, and is intended to protect the delicate structures 
within. It is so strong, that a sheep's eyeball may be 
trodden on with all the weight of the body, without 
being made to burst by the pressure. 

This coat gives place in the front of the eye to a 
transparent circular plate, just as in a watch the gold 
or silver case gives place to a glass crystal over the face. 
This transparent plate is the cornea, meaning " a horn." 

It forms a kind of rounded window for the eye. 2 
The polish and transparency of the cornea are kept up 
by frequent, unconscious winking, which keeps it moist 
and free from dust. 

The second coat (choroid) is much more delicate in 

1 1, Sclerotic ; 2, Choroid ; 3, Retina. 

2 The cornea can be best seen by looking at it from the side, or by seeing the 
reflection of a window-sash upon its surface. We usually look directly through 
it, and see only the colored iris behind. 



224 YOUNG FOLKS PHYSIOLOGY 

structure, and is rich in blood-vessels and nerves. It is 
lined with a thick black coating, designed to absorb the 
surplus rays of light, which would otherwise cause a 
blurred or confused vision. 

The retina, meaning "a net," the innermost coat of 
the eyeball, is an extremely delicate film, which covers 
the inner surface of the choroid. It is a sensitive net- 
work, made up of fibres proceeding from the optic 
nerve, spread out over the inner surface of the eye. 1 
It is the retina that makes the eye sensitive to light, so 
that we may well call it the actual or essential organ of 
sight. 

188. The Inside of the Eye. — To get a clear idea 
of the inside parts of the eye, let us imagine an eye- 
ball cut through the middle from above downwards. 
Let us now start in front, and go backwards. We shall 
first see the cornea, which has just been described. 

We now reach a space called the front chamber of 
the eye. In this chamber, and behind the cornea, 
hangs down a curtain, the iris, meaning "rainbow." It 
has a hole through its centre called the pupil, which 
appears as if it were a black spot. It is this curtain 
which gives the color to the eye. The iris has muscu- 
lar fibres which expand and contract, and thus make 
the pupil larger or smaller, according as the light is 
bright or dull. 

When the light is very strong and brilliant, the iris 
spreads its curtain farther over the pupil in order to 

i The retina is a film onl)' 1-120 of an inch thick, yet ten distinct layers have 
been described. 



THE SPECIAL SENSES 225 

shut out some of the rays. When the light is faint, 
the curtain is drawn back from the pupil in order to 
admit as many rays of light as possible. The black 




Fig. 72. — Section of Eyeball. 

appearance of the pupil is due to the thick black coat- 
ing which lines the inside of the choroid. It is like 
looking through a small window into a room in which 
the walls are hung with black paper. 

Just behind the iris is a clear, transparent, jelly- 
like body, called the crystalline lens. It is convex, or 
rounded, both back and front, and is about one-third of 
an inch in diameter. It is shut up in a kind of trans- 
parent bag, and is held in its place by a number of little 
bands. The crystalline lens separates the front cham- 
ber of the eye from the back chamber. 



226 YOUNG FOLKS' PHYSIOLOGY 

The front chamber is filled with a clear, watery fluid 
called the aqueous, or watery, humor. 

The back chamber also contains a jelly-like fluid 
called the vitreous, or glassy, humor. 1 Both the aque- 
ous and the vitreous humors exercise some nutritive 
action on the adjacent parts, and help to support and 
keep tense the coats of the eyeball. 

189. Mechanism of Vision. — Let us now trace the 
course of the rays of light going from any luminous 
body — a lighted candle, for example — through the 
different parts of the eye. Imagine the candle to be 
placed at about the ordinary distance of distinct vision 
(about ten inches) in the front of the eye. 

Some of the rays fall on the outer coat, or the 
" white, of the eye," and, being reflected, take no part 
in vision. The more central rays fall upon the cornea. 
Some of these are reflected, giving to the surface of 
the eye its beautiful, glistening appearance. 

Other rays pass through it, are brought nearer by 
refraction, and enter the aqueous humor, which also 
slightly bends them. Those which fall on, and pass 
through, the outer part of the cornea, are stopped by 
the iris, and are either reflected or absorbed by it. 
Those which fall upon its more central part pass 
through the pupil. 

Now, if the rays of light passed directly to the 
retina, they would pass in parallel lines, and produce 

1 This glassy humor, even in healthy eyes, contains little bodies called "flitting 
flies," which sometimes frighten people who notice them, greatly magnified, mov- 
ing up and down like strings of tiny bright beads. They are more plainly seen 
when looking at the bright sky or a white ceiling. They are in every eye, and can 
do no harm. 



THE SPECIAL SENSES 227 

the impression of light, but everything would be dim 
and confused. Therefore it is necessary that the rays 
coming from any object should be brought together 
(converged) by being bent (refracted). That is, they 
must be refracted, and brought to a focus. 

This is done to a certain extent by the cornea and 
the fluids, or "humors," of the eye, but mainly by the 
crystalline lens. This is a familiar fact in the use of 
any optical instrument. The boy changes the focus of 
his spy-glass by pulling its tubes in or out. When the 
lady looks from a distant to a near object with her 
opera-glass, she changes the focus by turning the 
adjusting-screw. 

Now, it is the duty of the crystalline lens to bring 
the rays of light together as they pass through it r and 
to bring them to a focus on the retina. A tiny muscle, 
called the ciliary, or hair-like muscle, does for the eye 
what the adjusting-screw does for the opera-glass. As 
it contracts and relaxes, the elastic lens, held in its 
place by delicate cords, becomes more rounded or flat- 
ter, just as we may wish to look at distant or near ob- 
jects. 

Suppose we wish to look at an object close at hand. 
The little muscle contracts ; and the layers of mem- 
branes, between which the lens lies, are the least bit 
relaxed ; and, because it is elastic, the lens becomes 
more rounded, or convex, thus bringing the rays of 
light to a proper focus. If we wish to look at any ob- 
ject a long distance off, the membranes are drawn 
tight by the muscle to which they are tied, and the 
lens is flattened. 



228 



YOUNG FOLKS PHYSIOLOGY 



In other words, our eyes adjust, or accommodate, 
themselves to the varying distances of objects ; just as 
the photographer pushes in or out the lens of his cam- 
era with his hand, so as to bring it farther or nearer 
from the surface which receives the image. 




Fig. 73. — Muscles of the Eyeball. 



The rays of light are now ready to be brought to a 
focus on the sensitive retina. The iris has regulated 
with wonderful skill the proper amount of light ; and 
the lens, with the greatest exactness, has focussed the 
rays on the retina. The dark surface of the middle 
coat acts to absorb the excess of light, and thus prevent 
the reflection which would disturb accurate vision. 

As a result, an exact but inverted image is formed 
on the retina. The impression is carried to the brain 



THE SPECIAL SENSES 229 

by the fibres of the optic nerve, which are spread out 
on this wonderfully sensitive membrane. 

190. The Muscles of the Eye. — The eyeball is rolled 
and moved about by six muscles. They spring from 
the back part of the bony orbits, and are fastened to 
the front part of the eyeball by means of tendons. 
Four of these muscles — the recti or straight muscles — : 
move the eye up or down, and to the right or left. 
The other two, the oblique, are so fastened that they 
turn the eyeball in one direction or another. Some- 
times one or more of these muscles pull unequally, and 
a " squint " or " cross-eye " is produced. 

191. The Eyelids and Eyebrows. — The eye, delicate 
organ that it is, is protected and kept clean by its 
eyelids, eyelashes, and eyebrows. 

The eyelids are thin, flexible covers, or shutters, which 
protect the front of the eyeballs. They are thin plates 
of gristle covered with skin. They are lined on the 
inner side with a very delicate membrane called the 
conjunctiva, because it is also joined to the eyeball by a 
fold. 1 It pours out an oily fluid to prevent friction 
between the surfaces. 

This fluid, together with a constant flow of tears, 
keeps the cornea moist, and free from dust. The edges 

1 This membrane covers the front part of the sclerotic, the whole of the 
visible portion, and, lining the walls of the tear-duct, becomes continuous with 
the mucous membrane of the nose and throat, and, therefore, usually takes a part 
in a " cold in the head." 

It is, ordinarily, nearly white, with perhaps a few of the larger blood-vessels 
seen winding through it, but is very easily congested by local injury, or inflamma- 
tion, particularly of the head, as in the case of the " blood-shot " eye. The 
characteristic yellow tinge of the eye in jaundice is due to the coloring-matter of 
the bile deposited in the conjunctiva. 



230 YOUNG FOLKS PHYSIOLOGY 

of the eyelids are provided with a fringe of fine hairs, 
the eyelashes, which help shade the eye, and shield it 
from dust. 

The eyebrows form a protecting and shading ridge 
over the eyes ; while the thick fringe of hairs, arranged 
somewhat like the straw on a thatched roof, prevents 
the sweat from rolling into the eyes as it trickles down 
the forehead. 

192. The Tears. — Nature provides a special fluid to 
protect the eye. This fluid is called the tears. 

The tear-apparatus consists of the gland for secret- 
ing tears, and the passages for draining them off. This 
gland pours out the tears over the surface of the eye, 
moistening it by the winking of the lids, and making 
its movements easy. 

The tears are now taken up, and carried off, by two 
fine tubes, one in the upper and one in the lower lid, 
which unite, and form the tear-duct, which leads into 
the nose. The ordinary flow of tears is thus drained off. 

Local irritation or mental emotion may excite an 
excessive flow, which the canals cannot carry off. The 
tears then overflow, and run down the cheeks. This is 
called crying, or weeping. Nature kindly greases the 
edges of the eyelids, to prevent, to a certain extent, 
the overflow of tears. 

193. Color-blindness. — Color-blindness is the in- 
ability to tell certain colors. It is sometimes produced 
bv sickness ; but generally it exists at birth, and is often 
hereditary. 1 This defect of sight is quite common. 

1 Some years ago a physician gave a history of color-blindness which had 
existed in five generations of his own family. 



THE SPECIAL SENSES 23 1 

Out of the many thousands that have been examined, 
it is found that four or five per cent are color-blind. 
A person may be color-blind, and not know it until the 
defect is accidentally revealed. 

This is a matter of the utmost practical importance to 
those employed on railroads, vessels, and other places 
where colored signals are used. Some are only partially 
color-blind, while others are wholly so. The most 
common form of color-blindness is that in which one 
fails to distinguish red. 

194. Near-sight and Far-sight. — All eyes are not 
perfect. Near-sight is a common defect of vision. In the 
healthy eye, the rays of light are brought to a focus on 
the retina. But in some eyes the image is blurred ; 
the outer coat, bulging backward, making the eyeball 
a little too long, thus bringing the rays of light to a 
focus before they reach the retina. A person with 
such an eye is said to be " near-sighted." 

It may exist at birth, and is very often hereditary. 
It is acquired by overstraining the eyes, in reading too 
fine print, by reading by a dim or imperfect light, and in 
many other ways. This defect is common with those 
who use their eyes much in reading, writing, and study. 
Sailors, farmers, and others who work out-doors, are 
rarely near-sighted. There has been found to be a 
steady increase of near-sightedness during the period 
of childhood and youth, especially among school-children. 
The statistics are so startling, that the subject is really 
one for the most serious consideration. Near-sighted- 
ness, in many cases, is a serious disease, which demands 
the most careful and skilful treatment by some good 



232 YOUNG FOLKS PHYSIOLOGY 

oculist. Teachers can do much to check the ill effects 
of this disease among their pupils. 

In far-sight the eyeball is too short, or the lens may 
be too flat. The rays of light are not brought to a 
focus. As a result, the image is blurred. The oculist 
can easily advise the proper kind of glasses to correct 
both of these defects of vision. 

195. Care of the Eyes. — The eye is an exceedingly 
delicate and sensitive little machine. It is an easy 
matter to get it out of order, and very tedious to 
restore it to health again. The eyes are often weak 
after certain sicknesses. The utmost care must be 
taken of them during and after an attack of measles 
and scarlet fever. 

The habit of reading the daily papers, with their 
blurred and indistinct type, in a car or carriage, is a 
severe strain on the eyes. We have to change the 
focus to suit the variation in the distance between the 
eyes and print caused by the constant jarring. It is a 
dangerous practice to read in bed at night, or while 
lying on a sofa or lounge in a darkened room. The 
outer muscles of the eyeball are put to a severe strain. 
The small type, poor paper, and press-work of the many 
cheap editions of popular books, now so commonly read, 
are very frequent causes of weak and diseased eyes. 

The direction in which the light comes, is an impor- 
tant matter. The worst direction of all is that from in 
front. The direct light should fall upon the print from 
above, and from the left side. The nearer an artificial 
light can come to a mellow daylight, the better. The 
flickering light from the ordinary "fish-tail" gas-burner 



THE SPECIAL SENSES 233 

is always bad. Its light should be regulated by shades 
and globes. Recently invented round and hollow burn- 
ers, used with kerosene oil, give an excellent light. 

After reading steadily for some time, we should rest 
the eyes by looking at some distant object, even if only 
for a minute. A person should never read, write, sew, 
stitch, or otherwise use the eyes, when they tingle or 
smart, or the sight is dim or blurred. The eyes are 
weary, and need a rest. 

Using the eyes at dusk, or by artificial light in the 
early morning, is apt to lead to serious disorders of 
vision. The eyes should never be rubbed, or the fingers 
roughly poked into them at any time, and much less 
when they are irritated by getting some foreign sub- 
stance into them. The sooner it is removed, the better. 
Rubbing the eye, or pulling the eyelids, only makes a 
bad matter worse. When the eyes smart after going to 
bed, or tingle, and are " bloodshot" on getting up the 
next morning, it is safe to conclude that they have been 
overtasked, and need rest. 

It is not a wise economy to tamper with one's eyes 
when they are ailing. Better to do nothing than do 
the wrong thing. If a few days of rest do not give any 
relief, a good oculist should at once be consulted. 

196. Effect of Alcohol and Tobacco upon the 
Special Senses. — We have already learned that alco- 
hol in a general way dulls or weakens the nerves. 
Hence it must have a similar effect upon the nerves of 
sensation. As a matter of fact, alcoholic liquors and 
tobacco dull the senses, and even provoke changes in 
the sense-organs themselves. 



234 YOUNG FOLKS' PHYSIOLOGY 

Thus, strong drink inflames the throat, and then the 
Eustachian tube, and so indirectly injures the sense of 
hearing. It lessens the quickness and the acuteness 
of hearing. Tobacco, also, often irritates the lining of 
the throat and nose. This inflammation is apt to ex- 
tend up the tube and involve the delicate structure of 
the middle ear, thereby causing some defect in hearing, 
such as a difficulty in hearing sounds that are very soft 
or very loud. 

Alcoholic liquors often produce congestion of the 
eyes and an irritation of the delicate lining of the eye- 
lids. Even in very small amounts alcohol lessens the 
acuteness as well as the quickness of vision. An im- 
moderate use of strong drink occasionally produces 
disease of the retina and the optic nerve. 

Tobacco smoke irritates the eyes. It may cause sharp 
pain and a redness of the eyeballs. Sometimes images 
are retained for some time after the eye has ceased to 
look at objects. This may be due to the effect of the 
poison of tobacco upon the retina. Smokers occasion- 
ally suffer from a feeble and" confused vision, due to a 
partial paralysis of the optic nerve. It is also claimed, 
by careful students of the subject, that the weak and 
imperfect vision of many young people of our day is 
due to the smoking habits of their fathers. 

Cigarettes are especially hurtful to the throat and 
the eyes. They produce an inflammation of the lining 
membrane. An atmosphere laden with tobacco smoke 
often irritates the lining of the bronchial passages. 



EXCRETION 235 



CHAPTER XIII 

EXCRETION 

197. Getting Rid of Waste Matters. — Our bodies 
are never the same for a single moment. With every 
breath, and with every beat of the heart, they are ever 
changing. Wear and waste vie with growth and 
repair. 

We eat food to supply the bodily engine with fuel, 
and breathe in oxygen to feed the furnace-fire. With 
a steady burning, but without light, the engine pro- 
duces not only motion and heat, but uses a part of its 
own energy to make its own repairs. Not this alone, 
but it even gets rid of its own soot, clinkers, and ashes, 
which would otherwise clog the machinery, and finally 
stop it. 

We have already learned that it is the ceaseless 
blood-current which carries fresh fuel, in the shape of 
the nutrient part of food, to the tissues, and is a kind of 
a sewer-stream that rids them of waste matters. The 
blood is ever being made rich by some things, and is 
ever getting rid of other things. The blood carries fuel 
to the tissues of the body. A slow burning takes 
place : the waste or ashes must be got rid of. 

198. Principal Waste Matters of the Body. — What 
are these waste matters ? If we take a piece of beef, 
dry it, and burn it, we shall find that it is changed into 



236 YOUNG FOLKS' PHYSIOLOGY 

four things, — water, carbonic acid, ammonia, and ashes. 
Now, this slow burning of our tissues is really the same 
thing. Hence, in whatever way the body is burned, or 
oxidized, whether in a furnace, or while it is' living, 
the end is always the same : — 

TYater, Carbonic Acid, a kind of ammonia called urea, 
and a small quantity of salts, or ashes. 1 

Besides the water which comes from the burning of 
the hydrogen of our food, we are drinking a great deal. 
We need to keep the tissues continually moist, to help 
dissolve the food, and also to wash the body inside, and 
cleanse it of its useless matters and impurities. As 
we wash the surface of the body to keep it clean, so 
Nature is ever giving our tissues a bath, to wash away 
their impurities. 

The red blood-disks, as we know, are the tiny boats 
which carry the oxygen breathed in by the lungs along 
the blood-stream to even' tissue. The tissues contain 
carbon ; and in some mysterious way, the oxygen 
unites with the carbon, and carbonic acid is formed. 

The tissues, like the muscles and nerves, yield nitro- 
gen. A partial decomposition takes place ; and the 
nitrogen is filtered out of the body, through the kid- 
neys, in the form of urea. It is a peculiar substance, 
something like ammonia, only more complex. Neither 
carbonic acid nor urea is fit to build tissue, or to set free 
energy. 

1 The body is made up of nitrogen, carbon, hydrogen, and oxygen, with sul- 
phur, phosphorus, and some other elements. The nitrogen and hydrogen go to 
form ammonia ; the hydrogen, with the oxygen of combustion, forms water : the 
carbon, carbonic acid : the phosphorus, sulphur, and other elements, go to form 
the various salts of the body. 



EXCRETION 237 

199. The Organs of Excretion. — The process by 
which the body gets rid. of its waste material is called 
excretion, meaning to separate from, or to sift out. 

The chief organs of excretion are the skin, the lungs, 
and the kidneys. 1 

The functions of all three of these organs are closely 
allied. The organs differ very much in appearance, 
but are built on the same principle. The blood, as it 
passes through the numberless capillary channels in 
them, is purified by a sifting process. The products 
of excretion are, as it were, sifted from the blood, and 
finally removed from the body. 

The lungs have also been described in a previous 
chapter. The duty of the lungs, as we have learned, 
is to excrete carbonic acid, watery vapor, and a small 
portion of worn-out animal matter. 

The structure of the skin has already been described. 
The main function of the skin, as we have seen, is to 
rid the body of water and other matters making up the 
sweat. 

200. The Kidneys. — These two important organs of 
excretion are of a brownish-red color, about four inches 
long, and two inches wide. They lie in the region of 
the loins, in front of the backbone, behind the intes- 
tines, one on each side, and are embedded in fat. A 
sheep's kidney is a familiar sight in a market. Now, 

1 " The three great channels, then, by which the blood purifies itself, by which 
it gets rid of its waste, are the lungs, the kidneys, and the skin. Through the 
lungs, carbonic acid and water escape ; through the kidneys, water, ammonia in 
the shape of urea, and various salts ; through the skin, water and a few salts. 
As the blood passes through lung, kidney, and skin, it throws off little by little 
the impurities which clog i^, one at one place, another at another, and returns 
from each purer and fresher." — Foster's Physiology. 



238 



YOUNG FOLKS PHYSIOLOGY 




Fig. 74. — The Kidneys. 



the kidneys of man have the same shape, and look 
like those of a sheep, only a little longer. 

The name " kidney " is popularly given to a kind of 

bean," the kidney 
bean," because of 
its resemblance to 
the shape of a kid- 
ney. 

A kidney is a bun- 
dle of long tubes, 
not so very unlike 
sweat - glands, all 
bound together into 
the kidney-shaped 
mass, whose appear- 
ance is familiar to 
us. The blood filters certain waste matters which be- 
come urine into these tubes, just as it secretes sweat 
into the sweat-glands. 

The urine is conveyed from the kidneys by two tubes, 
called the ureters, to the bladder, from which it is cast 
out of the body. Thus the kidneys purify the blood by 
carrying off urea and other waste matters dissolved in 
a large quantity of water. 1 

The kidneys are very important organs in helping to 
keep the blood pure. They rid it of the nitrogenous 
portion of the waste products which it is always re- 

1 The whole of this excretion is called the urine. It is in reality water, 
holding in solution urea and several other salts. The urine is constantly being 
secreted by the kidney. It is carried to the bladder by two tubes, the bladder 
serving as a reservoir. It collects in the bladder until that organ is nearly full, 
when it is emptied by contraction of its walls, aided by the abdominal muscles. 



EXCRETION 239 

ceiving. This is passed off for the most part in the 
urine. 

About three pints of fluid are daily discharged, on 
the average, through the kidneys, and a little over one 
ounce of urea, containing about two hundred and thirty 
grains of nitrogen. Out of the body, the urea soon 
changes into carbonic acid and ammonia. 

The kidneys also serve to carry off various chemical 
and mineral substances that are either foreign to the 
body, or are present in the blood in too large a propor- 
tion. Thus, if we should drink a glass of salt water, 
the kidneys would rid the body of the excess of salt. 

If the kidneys are inactive, or fail to excrete the 
nitrogenous waste matters, the work of many other 
organs is seriously impaired. The blood is poisoned, 
and death may result, from the powerful poisons left in 
the body. 

201. The Health of the Kidneys. — The kidneys 
are very busy organs. Their health is a matter of 
prime importance to every human life. We have al- 
ready become familiar with the hygiene of two great 
organs of excretion, — the skin and the lungs. These 
three sets of organs, then, working together in har- 
mony, like three groups of mechanics doing some diffi- 
cult work, keep the bodily machinery from getting 
clogged and choked with waste matters. 

If the balance of healthy life is to be maintained, 
these three great vital processes, or functions, must be 
carried on or regulated in strict harmony with each 
other. Thus, if the free action of the skin is inter- 
rupted, the kidneys have extra work to do. They make 



24O YOUNG FOLKS PHYSIOLOGY 

every effort to do the additional work that is thrown 
upon them ; but, sooner or later, they fail under the bur- 
den, and become diseased. s 

Again, a person may overstrain the kidneys by drink- 
ing any fluid in excessive amount. This is especially 
true of those wno drink enormous quantities of beer. 
This, in time, results in disease of these organs. In 
certain diseases, often due to the use of alcohol, the pre- 
cious albumen is drained off from the blood through 
the kidneys. 

Like the liver, the kidneys are often singled out by 
well-meaning people as a favorite seat of imaginary 
disease. If a person gets cold, strains the deep mus- 
cles of the back, or is otherwise crippled, he is too apt 
to speak of the " crick " in the back as a " trouble with 
my kidneys." 

The truth of the matter is, that the most serious and 
insidious diseases of these organs are rarely accom- 
panied with pain. Hence the popular use of all kinds 
of nostrums, shrewdly prepared to increase the flow of 
the urine, and called a " sure cure " for all kidney ail- 
ments, rarely does any good. Nine times out of ten, all 
such aches and pains in the back are due to a severe 
cold or a muscular strain. 

202. Effect of Alcohol upon the Kidneys. — The 
kidneys are quick to feel the effects of alcohol. They 
become diseased in various ways, and often to a fatal 
extent even by what is called the "moderate" use of 
alcohol. 

Indeed, so powerful is the alcoholic poison on the 
vital action and structure of the kidneys, that physicians 



EXCRETION 241 

who are best fitted to judge, say that at least three- 
fourths of the instances of kidney disease are due to 
the use of alcohol, and to this cause alone. 

In the first place, alcohol excites the kidneys to over- 
action by a chronic dilatation of the blood-vessels, thus 
irritating the delicate excreting tubes of these organs. 
Again, it is known that hindering the changes of tissue- 
waste prevents the proper reduction into urea. 

Now, it is generally admitted, that alcohol does, in 
some measure, hinder the proper changes in the tissue- 
waste. Hence a large part passes out in a less soluble 
and more irritating form. 

Either from this cause, or from repeated congestion 
and irritation, alcohol leads at last to widespread dis- 
ease of these vital organs in a large number of cases. 
The structure of the kidneys may be so changed from 
the use of alcoholic drinks, that urea is not properly 
excreted ; and albumen is drained off instead. 

This may give rise to that peculiarly insidious and 
fatal disease known as " Bright's disease." 1 It is now 
generally admitted, that the habit of drinking alcoholic 
liquors is a frequent cause of this dreaded disease. 

The structure of the kidney is so changed, that there 
is no thoroughfare for the natural amount of urea. Thus, 

1 So called from the name of the English physician who first described the 
disease. 

" The relation to Bright's disease is not so clearly made out as is assumed by 
some writers, though I must confess to myself sharing the popular belief that alco- 
hol is one among its most important causes." — Robert T. Edes, M.D. 

" Whether alcohol or cold be the sharper blade of the shears so apt to cut short 
life's thread by Bright's disease, I care not greatly, inasmuch as it cannot be 
questioned that both of them have that tendency." — Chambers's Diet in Health. 



242 YOUNG FOLKS' PHYSIOLOGY 

the ordinary safety-valve is shut off. The albumen, so 
essential to healthy blood, is filtered off through the 
diseased organ ; and the waste matters — the ashes — 
get into the blood, and poison it. 1 

1 " As a primary affection, Bright's Disease occurs especially in persons 
addicted to intemperance." — Austin Flint, M.D. 



THE THROAT AND VOICE 243 



CHAPTER XIV 

THE THROAT AND VOICE 

203. The Throat. — The throat is the common 
passage through which food goes to the stomach, and 
air to the lungs. 

It is shut in and protected by the muscles and bones 
of the neck. Both the outside of the neck and its 
interior, or the throat, are exposed to sudden and fre- 
quent changes of the weather, which oftentimes lead 
to diseases of the throat and the lungs. We have already 
learned something of the food and air passages in the 
preceding chapters. 

The only way to get a proper idea of the throat, is to 
look into a friend's mouth. First let the person hold his 
mouth wide open, facing a good light. Hold the 
tongue down with the handle of a spoon. We are 
already familiar with the hard palate, soft palate, uvula, 
and tonsils. Now, on looking directly past these 
organs, we see the beginning of a passage called the 
pharynx, which is common to the two highways by which 
air and food are taken into the inside of the body. 
Look sharp at the top, and we see the air-passage which 
leads to the nose. The air-tract at the top has two out- 
lets, the mouth and the nose. 

Now, if we pull the tongue forcibly forward, a little 
curved ridge is sometimes seen behind it. This is the 
epiglottis, which, as we already know, is the trap-door 



244 YOUNG FOLKS PHYSIOLOGY 

which shuts down, like the lid of a box, over the top of 
the air-passage, or windpipe. 

The part of the throat directly opposite the line of 
vision, as we have just learned, is the back wall of the 
pharynx, which, as the gullet, or food-passage, continues 
downward. The pharynx runs up to the base of the 
skull behind, and ends in a kind of vaulted roof, shaped 
something like a crooked forefinger, or the top of an 
old-fashioned chaise. 

All the parts of this irregular-shaped region, known 
as the throat, are covered with a lining-membrane which 
secretes a fluid to keep them moist. 

204. Care of the Throat. — Exposed as it is to 
unhealthy and unwholesome air, irritating dusts of the 
street and the workshop, it is not strange that the deli- 
cate lining of the throat becomes inflamed. The result 
is an ailment which is popularly called " sore throat." 
Almost every one has at times suffered more or less 
from it. The most frequent cause of throat-disease 
is the direct action of cold upon the heated body, 
especially during profuse perspiration. 

Eating hot food, and then drinking ice-water to 
cool the parts, is another source of sore throat. We 
may overstrain the muscles of the throat in loud talking, 
shouting, or by reading aloud too much. All classes of 
persons who strain the voice, or misuse it, often suffer 
from a severe kind of sore throat, popularly called 
"clergyman's sore throat." 

Persons subject to throat-disease should take great 
pains to wear proper underclothing. Daily baths are 
excellent tonics to the skin, and thus serve indirectly 



THE THROAT AND VOICE 



245 



to harden one liable to throat ailments to ordinary 
changes in the weather. Muffling the neck in scarfs, 
furs, and wraps is not a good plan, — it only increases 
the liability to catch cold, — except, perhaps, during the 
coldest weather, or during unusual exposure to cold. 

205. The Organ of Speech. — As we have been told 
in a preceding section, the box-lik.e top of the wind- 
pipe is called the larynx, meaning 
"top of the wind-pipe." It is com- 
posed mainly of cartilage. 

The sides of this box are made 
of two flat pieces of cartilage shaped 
like a shield. 1 The edges unite in 
front, and project to form " Adam's 
apple," which is easily felt, and is 
plainly to be seen on most lean 
people, especially spare men. This 
cartilage shelters the delicate and 
movable structure within, and 
shields it from injury without. 
The epiglottis is attached to the 
inner and upper part of this carti- 
lage. 

Just below is a ring-shaped car- 
tilage. 2 It is broad behind, quite 
narrow in front, much like a seal- 
ring. This is easily detected under the skin, a little 
below the Adam's apple. Two slender, ladle-shaped car- 
tilages 3 are placed on the top of the back part of the 
cricoid. They work with a ball-and-socket joint, and 

1 Thyroid cartilage. 2 Cricoid cartilage. 3 Arytenoid cartilages. 




Fig. 75. — A Front View 
of the Exterior of the Carti- 
lages of the Larynx : 1, Up- 
per Ring of the Windpipe; 
2, Cricoid, or Ring-like Car- 
tilage, the Base of the Lar- 
ynx; 3, Thyroid, or Shield- 
like Cartilage (the figure 3 is 
on the Adam's apple); 4, 
Epiglottis; M, a Membrane 
uniting the Cricoid and the 
Thyroid Cartilages. 



246 



YOUNG FOLKS PHYSIOLOGY 



have tiny muscles which regulate their movements with 
the utmost accuracy and regularity. From each of 
these two cartilages a band of elastic tissue passes for- 
ward, and is tied to the inner and front part of the 
shield-like cartilage towards its lower edge. 

These two bands, called the 
yocal cords, are narrow strips of 
firm, fibrous material, with a chink- 
like opening called the glottis, 
meaning the "mouth-piece of a 
flute." This is the real organ of 
voice. All the air which goes out 
or into the lungs must go through 
the glottis. Muscles and cartilages 
act to tighten or loosen these 
cords. 

As the air is forced through the 
glottis, these bands are set into 
vibration, and thus sound is pro- 
duced. When the cords are tightly 
stretched, and near together, they 
vibrate more rapidly, and send out 
a high tone: but when they are 
less tense, and wider apart, their vibrations are less 
rapid ; and a relatively low tone is the result. During 
ordinary breathing, the vocal cords are widely separated. 
206. How the Voice is produced. — If the air be 
driven out of the lungs by an act of expiration, when 
the cords are in a state of tension, they vibrate, and 
produce the sound called the voice. 

The different musical sounds produced in singing 




Fig. 76. — Interior View of 
Right half of the Larynx : 
1, Upper Ring of the Wind- 
pipe; 2, Cricoid Cartilage; 
3, Thyroid Cartilage; 4, Epi- 
glottis; 5, Vocal Band (Vocal 
Cord) ; 6, Arytenoid Carti- 
lage; 7, Ventricular Band 
(so-called False Vocal Cord). 




THE THROAT AND VOICE 247 

depend upon the varying degree of tension of the vocal 
cords. The compass of the voice depends upon the 
extent to which the variations can take place. A prac- 
tised singer can, at will, give the requisite tension for 
the production of any particular note. 

The quality of a voice depends 
upon the structure of the larynx. In 
women and children 1 the larynx is 
smaller, and the vocal cords shorter, 
than in men: consequently their 
voices have a higher pitch. The FlG . 77 . ^ he vocai 
longer the cords, and the larger the £ords durin s Ins P ira " 
larynx, the deeper the voice. 

Voice may exist without speech, as in many animals. 
Speech is the voice modified by the throat, teeth, palate, 
nose, tongue, and lips. In whispering, words are ut- 
tered without that vibration which gives vocal sound. 

207. Effect of Alcohol and Tobacco uponthe Throat 
and Voice. — The peculiar harsh tone to the voice of 
those given to strong drink is a familiar fact. The 
reason for it is plain. Alcoholic liquors inflame and 
irritate the delicate lining of the throat and of the 
vocal cords. This, after a time, makes the mucous 
membrane lining thick and rough. 

Alcohol weakens the vocal efforts. Hence vocalists, 
clergymen, and public speakers find that alcoholic 
drinks impair the voice. 

Tobacco tends always to weaken the vocal effort. 

1 About the age of fourteen, the vocal organs begin to enlarge rapidly. It 
causes a " change of voice," as it is commonly called, and is most marked in boys. 
The voices of children are very much alike in both sexes. 



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SIMPLE MATTERS OF EVERY-DAY HEALTH 249 



CHAPTER XV 

SIMPLE MATTERS OF EVERY-DAY HEALTH.— 
WHAT TO DO, AND HOW TO DO IT 

208. Accidents and Emergencies. — Accidents are 
liable to happen to any one. A friend may cut his 
leg or foot with a scythe or knife ; a child may acci- 
dentally swallow some laudanum, or push a bean into his 
nose or ear ; a teamster is brought in with his ears frost- 
bitten ; a small boy falls into the river, and is brought 
out apparently drowned ; some one of our own family 
may be taken suddenly sick with some contagious 
disease, or may be suffocated with coal-gas. 

All these, and many other things of a like nature, 
are likely to call for a cool head, a steady hand, and 
some practical knowledge of what is to be done. 
These homely details of health may be easily mastered. 
It is simply the practical application of what we have 
studied thus far about our bodies. 

The dry facts of anatomy and physiology become 
tenfold more attractive and instructive to us when we 
thus learn to apply what we have studied to the simple 
details of daily health. 

Let us now try to become familiar with a few of 
the simplest helps in ordinary accidents, emergencies, 
and in other similar matters of personal health. 

209. Poultices, how to make them, and when to use 
them — There are many occasions when the right kind 



250 YOUNG FOLKS PHYSIOLOGY 

of a poultice y made in the right way, and applied to the 
right spot, will give a great deal of relief from sudden 
and severe pains in the chest, abdomen, and elsewhere. 
The materials are so handy, the relief afforded so great, 
and the risk of doing harm so little, that even a child 
should know how to make a poultice, or put on a hot 
outward application. 

Foremost amongst these household remedies is mus- 
tard. To make a "mustard paste," as it is called, mix 
one even tablespoonful of mustard and three or four of 
fine flour with enough water or vinegar to make the 
mixture an even paste. Spread it neatly with a table- 
knife on a piece of old linen, or even cotton cloth, of 
the required size. Cover the face of the paste with a 
thin piece of old muslin or linen. Now apply the plas- 
ter with its face down. 

Some skins are easily blistered with mustard, hence 
it must be watched. About twenty minutes is long 
enough to keep it on. If the skin smarts badly, and is 
quite red, the paste should be removed. Do not put 
mustard paste on children: their skin is easily blis- 
tered with it. 

A thicker paste, or a poultice proper, can be made 
out of flaxseed, oatmeal, rye-meal, ground slippery elm, 
or bread. A poultice to be of any good, and to hold 
its heat, should be from half an inch to an inch thick. 

The way to make a good poultice is short and sim- 
ple. Stir the meal slowly into a bowl of boiling water, 
just as the old-fashioned "hasty-pudding" is made, 
until a thin and smooth dough is formed. Fold a piece 
of old linen of the right size in the middle ; spread the 



SIMPLE MATTERS OF EVERY-DAY HEALTH 25 1 

dough evenly on one-half of the cloth, and cover it 
with the other. The secret of using a poultice is to 
apply it hot, and keep it so by frequent changes. Keep 
the poultice mixture hot on the stove, use duplicate 
cloths, and have a fresh, hot poultice to exchange in an 
instant for the cold one. Never let a poultice get cold : 
it will do more harm than good. 

Flannel wrung out in hot water, and cloths heated 
dry, and applied to painful places, are called fomenta- 
tions. Simply dip the flannel, folded several times 
into the desired shape, into boiling water ; put it into 
a towel to protect the hands, and wring it out well. 
Apply it hot as possible, cover it carefully with larger 
pieces of flannel (oiled silk is the best of all), and use 
duplicate pieces to make the changes rapidly. 

These outward applications are useful to relieve sud- 
den cramps and pains in the abdomen and chest, due 
to severe colds, injuries, or sprains. Care should be 
taken to prevent the bedding or clothes from being 
wet or dampened. A "crick" or "stitch" in the side 
or back is quite common from overstraining certain 
muscles, and catching cold. A swollen face, due to an 
ulcerated tooth or neuralgia; flying pains in various 
parts of the body ; a colicky pain in the abdomen ; boils 
and other sores tending to "point," and very painful, — 
are a few of the many ailments for which poultices 
and outward applications will give a temporary relief 
from suffering. 

Rubber bags made to hold very hot water are useful 
helps in keeping outward applications constantly hot. 



::: YOUNG FOLKS PHYSIOLOGY 

210. What to do for a Fainting Person. — Fainting 

little treatment is necessary. A fainting person should 
be laid flat at once. Give plenty of fresh air ; and dash 
cold water, if necessary, on the head and neck. Loosen 
all tight clothing. It is well enough to hold smelling- 
salts to the nose, to excite the nerves of sensation. 

211. Epileptic Fits, Convulsions of Children, etc. — 
Sufferers from "fits" are more or less common. There 
is often a peculiar cry, a loss of consciousness, a moment 
of rigidity, and violent convulsions come on : there is 
foaming at the mouth, the eyes are rolled up, and the 
tongue or lips are often bitten. 

Such a sufferer should be treated much the same as 
for fainting-fits. See that the person does not injure 
himself; crowd a corner of a folded handkerchief be- 
tween the teeth, to prevent biting of the lips or tongue. 
Persons who are subject to such fits should not go out 
alone very much, and never into crowded or excited 
gatherings of any kind. 

Children occasionally will eat some indigestible sub- 
stance, and suddenly be taken with convulsions. Give 
an emetic at once, and an enema of warm soapsuds. 
Put the child's feet and legs into a bath of hot mustard- 
water for fifteen minutes. 

2:2. Asphyxia, or Suffocation. — When for any 
reason the proper supply of oxygen is cut off, the 
tissues rapidly load up with carbonic acid. The blood 
turns dark, and does not circulate. The healthy red or 
pink look of the lips and finger-nails becomes a dusky 



SIMPLE MATTERS OF E VERY-DAY HEALTH 253 

purple. The person is suffering from a lack of oxygen ; 
that is, from asphyxia, or suffocation, meaning "absence 
of pulse." 

The first and essential thing to do is to give fresh 
air. Remove the person to the open air, loosen all 
tight clothing, dash on cold water, give hot water with 
a few drops of ammonia in it or hot ginger-tea, and, if 
necessary, use artificial respiration, as stated in the 
next section on apparent drowning. 

The chief dangers from poisoning by noxious gases 
come from the fumes of burning coal in the furnace, 
stove, or range; from " blowing out" gas, or turning it 
down, and having it blown out by a draught ; from the 
foul air often found in old wells; from the fumes of 
charcoal and the foul air of mines. 

213. Apparent Drowning. — Four things have hap- 
pened to a person nearly dead from drowning. First, 
he is unconscious, because he has not had enough 
oxygen. Second, he has sucked water into the air- 
passages, and it must be removed. Third, he is 
cold, and needs warmth. Fourth, his blood is so full 
of carbonic acid, that, the circulation is at the lowest 
ebb. 'What must be done ? 

Remove all tight clothing from the neck, chest, and 
waist. Sweep the forefinger, covered with a handker- 
chief or towel, round through the mouth, to free it from 
froth and mucus. Turn the body on the face, raising 
it a little, with the hands under the hips, to allow any 
water to run out from the air-passages. Take only a 
moment for this. 

Lay the person flat upon the back, with a folded 



-^54 



YOUNG FOLKS PHYSIOLOGY 



coat, or pad of any kind, to keep the shoulders raised 
a little. Remove all the wet, clinging clothing that is 
convenient. If in a room or sheltered place, strip the 
body, and wrap it in blankets, overcoats, etc. 

If at hand, use bottles of hot water, hot flats, or bags 
of hot sand round the limbs and feet. Watch the 




Fig. 78. — The process of artificial respiration : first step. 

tongue : it generally tends to slip back, and to shut off 
the air from the glottis. Wrap a coarse towel round 
the tip, and keep it well pulled forward. 

The main thing to do is to keep up artificial respira- 
tion until the natural breathing comes, or all hope is 
lost. This is the simplest way to do it : The person 
lies on the back ; let some one kneel behind the head. 
Grasp both arms near the elbows, and sweep them up- 
ward above the head until they nearly touch. Make 
a firm pull for a moment. This tends to fill the lungs 
with air by drawing the ribs up, and making the chest- 



SIMPLE MATTERS OF EVERY-DAY HEALTH 



255 



cavity larger. Now return the arms to the sides of 
the body until they press hard against the ribs. This 
tends to force out the air. This makes artificially a 
complete act of respiration. Repeat this act about 
fifteen times every minute. 

All this may be kept up for several hours. The first 




Fig. 79. — The process of artificial respiration : second step. 



sign of recovery is often seen in the slight pinkish tinge 
of the lips or finger-nails. Because the pulse cannot be 
felt at the wrist is of little account as a sign of death. 
Life may be present when only the most experienced 
ear can detect the faintest heart-beat. 

When a person can breathe, even a little, he can 
swallow. Put smelling-salts or hartshorn to the nose. 
Put one teaspoonful of the aromatic spirits of ammonia, 
or even of ammonia water, into a half -glass of hot water, 
and give a few teaspoonfuls of this mixture every three 



2$6 YOUNG FOLKS' PHYSIOLOGY 

minutes. Meanwhile do not fail to keep up artificial 
warmth in the most vigorous fashion. 

Do not move a person who is just beginning to 
breathe again from one place to another for some time, 
except when forced to do so from cold, or any pressing 
necessity. Above all things, do all that you do in 
right good earnest, and not in- a spasmodic, half-hearted 
sort of way. 

214. Sunstroke or Heatstroke. — This severe trouble 
is caused by an unnatural elevation of the bodily temper- 
ature by exposure to the direct rays of the sun, or from 
the extreme heat of close and confined rooms, as in the 
cook-rooms and laundries of hotel basements, from over- 
heated workshops, etc. The worst cases of " sun- 
stroke " often happen in places where the sun's rays 
never penetrate. 

There is sudden loss of consciousness, with deep, 
labored breathing, an intense burning heat of the skin, 
and a marked absence of sweat. The main thing is to 
lower the temperature. Strip off the clothing ; apply 
chopped ice, wrapped in flannel to the head. Rub ice 
over the chest, and place pieces under the armpits and 
at the sides. If there is no ice, use sheets or cloths 
wet with cold water. 

The body may be stripped, and sprinkled with ice- 
water from a common watering-pot. If the skin is cold, 
moist, or clammy, the trouble is due to heat-exhaustion. 
Give plenty of fresh air, but apply no cold to the body. 
Apply heat, and give hot drinks, like hot ginger tea. 
Remember that sunstroke or heatstroke is a dangerous 
matter. It may be followed by serious and permanent 



SIMPLE MATTERS OF EVERY-DAY HEALTH 257 

results. Persons who have once suffered in this way 
should carefully avoid any risk in the future. 
. 215. Broken Bones. — Send for a doctor at once. 
Loss of power, pain, and swelling are symptoms of a 
broken bone, that may be easily recognized. 

Broken limbs should always be handled with great 
care and tenderness. If the accident happens in the 
woods, the limb should be bound with handkerchiefs, 

How to carry an Injured Person. —"If injured persons have 
to be moved from one place to another, it is worth while to know how to 
do it with the greatest ease and safety to them. If a door or shutter or 
settee is at hand, any of these will make a good litter, with a blanket 
or shawls or coats for pillows. In lifting a person upon a stretcher, it 
should be laid with its foot at his head, so that both are in the same 
straight line. Then one or two persons should stand on each side of 
him, and, raising him from the ground, slip him upon the stretcher. This 
can be done smoothly and gently ; whereas, if a stretcher is laid alongside 
of an injured person, some of those who lift him will have to step back- 
wards over it, and in doing so are very apt to stumble. If a limb is 
crushed or broken, it may be laid upon a pillow, with bandages tied 
round the whole, so as to keep it from slipping about. Where an injured 
person can walk, he can get much help by putting his arms over the shoul- 
ders and round the necks of two others. In case of an injury where walk- 
ing is impossible, and lying down is not absolutely necessary, an injured 
person may be seated on a chair, and carried ; or he may sit upon a board 
or fence-rail, the ends of which are carried by two men, around whose 
necks he should place his arms, so as to steady himself ; or two men may 
carry him seated on their interlocked hands, in the way known to chil- 
dren as ' Lady to London.' To do this, each of two persons standing 
face to face should grasp his right fore-arm with his left hand (its back 
uppermost), then he should grasp his companion's free left fore-arm with 
his own free right hand (also with its back uppermost). When no litter 
can be gotten, the body may be supported by a man on each side, with 
their arms placed behind his chest and under his hips. In carrying an 
injured person upon a litter, or what serves for one, the bearers ought not 
to keep step ; but, when they are not using a litter they should keep 
step." — ; Dulles's Accidents and Emergencies. 



-r 



YOUNG FOLKS PHYSIOLOGY 



suspenders, or strips of clothing to a piece of board, 
pasteboard, 01 bark, padded with moss or grass, whicb 
will do well enough for a tem- 
porary splint. Always put a 
broken arm into a sling- after 
the splints are on 

["ever move the injured 
person until the limb is made 
safe from further injuries by 
putting it into splints. If 
you do not need to move 
the person, keep the limb in 
a natural, easy position, until 
the doctor comes. 







Fi'v - - imporary Fig. Si. — Showing- how a temporary 

splint may be put on to a broken leg. splint and a sling may be put on to a 

broken arm. 



Keep the patient warm. Do not give a drop of alco- 
holic liquor. 

Remember that this treatment for broken bones is 



SIMPLE MATTERS OF EVERY-DAY HEALTH 259 

only to enable the patient to be moved without further 
injury. A surgeon is required to set the broken limb. 

216. Burns or Scalds. — Burns or scalds are danger- 
ous in proportion to their extent and depth. A child 
may have one of his fingers burned off with less danger 
to life than an extensive scald of his back. 

After severe burns or scalds, remove the clothing 
with the greatest care. Do not pull, but carefully cut 
and coax, the clothes away from the burned places, 
taking some time for it. Save the skin unbroken if 
possible, taking care not to break the blisters. The 
secret of treatment is to avoid chafing, and to keep out 
the air. 

If the burn is slight, put on pads of soft linen soaked 
in a strong solution of baking-powder and water, one 
heaping tablespoonful to a cupful of water. It may be 
put on dry, and kept well covered with cotton-wool or 
bandages. " Carron oil " is one of the best applica- 
tions. It is simply half linseed-oil and half lime-water 
shaken together. Soak strips of old linen in this, and 
gently apply. Simple cold water is better than flour, 
cotton-batting, and other things which are apt to stick, 
and make an after-examination very painful. Re- 
member this : — 

A deep or extensive burn or scald should always have 
good medical attendance. 

217. Frost-bite. — The ears, toes, nose, and fingers 
are occasionally frozen or frost-bitten. No warm air, 
warm water, or fire is to be allowed near the frozen 
parts until the natural temperature is nearly restored. 
Great care must always be taken in the after-treatment, 



26o YOUNG FOLKS' PHYSIOLOGY 

lest serious results should follow. Rub the affected part 
gently with snow or snow-water in a cold room. The 
circulation should be restored very slowly. Hot milk 
with cayenne pepper, and hot ginger-tea should be 
freely given. 

218. Foreign Bodies in the Throat. — Bits of food and 
other small objects sometimes get lodged in the throat, 
and are easily got out by the forefinger, by sharp slaps 
on the back, or thrown out by vomiting. If it is a 
sliver from a toothpick, match, or fish-bone, it is no 
easy matter to remove it ; for it generally sticks into 
the lining of the passage. Holding a child up by the 
heels, with the head hanging down, and giving a few 
vigorous shakings, will often dislodge a foreign body 
when simpler means fail. 

If the object has actually passed into the windpipe, 
and followed by sudden fits of spasmodic coughing, 
with a dusky hue to the face and fingers, there is great 
danger of life. Surgical help must be called without 
delay. 

If a foreign body, like coins, pencils, keys, fruit-stones, 
etc., is swallowed, it is not wise to give a physic. Give 
plenty of hard-boiled eggs, cheese, and butter-crackers, 
so that the substance may be passed off in the natural 
way, in a bulky stool. 

219. Foreign Bodies in the Nose. — Children are apt 
to push marbles, beans, peas, fruit-stones, buttons, and 
other small objects, into the nose. Sometimes we can 
get the child to help by blowing the nose hard. At 
other times, a sharp blow between the shoulders will 
cause the substance to fall out. 



SIMPLE MATTERS OF EVERY-DAY HEALTH 26l 

Do not waste time, — especially if it is a pea or bean, 
which is apt to swell with the warmth and moisture, — 
but call in medical help at once if you do not meet 
with success. 

220. Foreign Bodies in the Ear. — It is a much more 
delicate matter to get foreign bodies out of the ear than 
from the nose. The simplest thing is to syringe in a 
little warm water, which will often wash out the sub- 
stance. If live insects get into the ear, drop in a little 
sweet-oil, salt and water, or even molasses. 

If the tip of the ear is pulled up gently, the liquid 
will flow-in more readily. If a light is held close to 
the outside ear, the insect may be coaxed to crawl out 
towards the outer opening of the ear, being attracted 
by the bright flame. 

221. Foreign Bodies in the Eye. — Cinders, parti- 
cles of dust, and other small substances, often get into 
the eye, and cause much pain. Do not rub the eye, 
however much you may feel like it. It will only make 
bad matters worse. Often the copious flow of tears 
will wash the substance away. It is sometimes seen, 
and removed simply by the twisted corner of a handker- 
chief carefully used. If it is not removed, or even 
found, in this way, the upper lid must be turned back. 

This is the way to do ' it : Seize the lashes between 
the thumb and forefinger, and draw the edge of the lid 
away from the eyeball. Now, telling the patient to 
look down, press a slender lead-pencil or penholder 
against the lid, parallel to and above the edge, and then 
pull the edge up, and turn it over the pencil by means 
of the lashes. 



262 YOUNG FOLKS' PHYSIOLOGY 

The eye is now easily examined, and usually the 
foreign body is easily seen and removed. Do not in- 
crease the trouble by "poking" at the eye after you 
fail, but get at once skilled help. After the substance 
has been removed, bathe the eye for a time with hot 
water. If lime gets into the eye, use large quantities 
of vinegar or lemon-juice and water, one teaspoonful to 
a teacupful of water. 

How to remove a Foreign Substance from the Eye. — " Lay your 

finger on the cheek and draw the lower lid gently down, while the per- 
son looks as much upward as possible, and we shall see about the whole 
extent of the lower portion of the conjunctiva; and thus if any foreign 
substance is there, it will be readily detected, and easily wiped away with 
a folded soft rag or handkerchief. Both lids have a piece of cartilage 
in them to stiffen them, like pasteboard, and keep them fitting close to 
the eyeball. 

" The upper portion of this conjunctival sac can only be seen by turn- 
ing over the upper lid. The way to do this is to let the person look down 
with the eyes closed. Taking hold of the lashes with one hand, and apply- 
ing a pencil, or some small, round, smooth object, over the lid above the 
globe, we lift the lashes out and up, warning the person to still keep look- 
ing down. The lid will suddenly turn over with a little spring from 
the bending of the cartilage. 

" In this way nearly the whole of the conjunctival sac will be exposed, 
and any foreign body wiped away, as above described. But suppose no 
friend or oculist is by us to do this. The next best thing is to take hold 
of the lashes of the upper lid, and draw it forward and downward over 
the lower one, blowing the nose violently with the other hand at the 
same time. 

" If the foreign substance is on the cornea, take a strip of paper not 
stiffer than ordinary writing-paper, about a quarter of an inch wide, and 
roll it up as if you were going to make a candle-lighter. Look at the 
lower end, and you will see it comes to a point. With this point now you 
may safely attempt to remove any foreign substance from the cornea. The 
tears which will flow soften the paper, and prevent injury to the delicate 
covering membrane of the cornea."— Dr. B. Joy Jeffries. 



SIMPLE MATTERS OF EVERY-DAY HEALTH 263 



HEMORRHAGE — BLEEDING. 

222. Injuries to the Blood-vessels. — It is very im- 
portant to know the difference between the bleeding of 
an artery and that of a vein. If an artery bleeds, the 
blood spurts in a stream, or leaps in jets, comes very 
rapidly, and is of a bright scarlet color. If a vein 
bleeds, the blood slowly oozes out, or flows in a steady 
stream, and is of a dark and purple color. 

Bleeding from an artery is a dangerous matter in pro- 
portion to the size of the vessel, and life itself may be 
speedily lost ; while hemorrhage from the veins is rarely 
a serious injury, and generally stops of itself, aided, if 
need be, by hot water, deep pressure, some form of iron 
styptic, or even strong alum-water. When an artery is 
bleeding, always remember to make deep pressure be- 
tween the wound and the heart. In all cases where com- 
mon sense would suggest it, send at once for the doctor. 

Meanwhile there is something to do. Keep cool, re- 
member the simplest facts of the anatomy we have just 
studied, and do not be afraid to act at once. A reso- 
lute grip in the right place with firm fingers will do well 
enough, until a twisted handkerchief, stout cord, shoe- 
string, or suspender is ready to take its place. If the 
artery is of some size, make a knot in whatever is used, 
and bring the pressure of the knot to bear over the 
artery. If the flow of blood does not stop, change the 
pressure until the right spot is found. 

Sometimes it will do to seize a handful of dry earth, 
and crowd it down into the bleeding wound, with a 
firm pressure. Strips of an old handkerchief, under- 



264 



YOUNG FOLKS PHYSIOLOGY 



clothing, or cotton wadding, might be stuffed into the 
wound, keeping up the pressure all the time. 

Let us try to keep in mind the principal places to 
apply pressure when arteries are 
injured and bleeding. 

If in the finger, grasp it with 
the thumb and forefinger, and 
pinch it firmly on each side : if 
in the hand, press on the bleed- 
ing spot, or press with the 
thumb just above, and in front 
of, the wrist. 

For injuries below the elbow, 
grasp the upper part of the arm 
with the hands, and squeeze 
hard. The main artery runs in 





Fig. 82. — Showing how a handker- 
chief and a stick may be applied to the 
arm to stop bleeding. 



Fig. 83.— Showing how a bandage 
may be used to stop bleeding from an 
artery in the arm. 



the middle line of the bend of the elbow. Tie the 
knotted cord here, and bend the fore-arm so as to press 
hard against the knot. 

For the upper arm, press with the fingers against the 



SIMPLE MATTERS OF EVERY-DAY HEALTH 265 

bone on the inner side, and just on the edge of the 
swell of the biceps muscle. Now we are ready for the 
knotted cord. Take a stout stick of wood, about a foot 
long, and twist the cord hard with it, bringing the knot 
firmly over the artery. 

For the foot or leg, pressure as before, in the hollow 
behind the knee, just above the calf of the leg. Bend 
the thigh towards the abdomen, and bring the leg up 
against the thigh, with the knot in the bend of the 
knee. A knife may glance, and cut the great femoral 
artery. Remember it runs deep in the inside of the 
thigh, but is exposed when it comes out of the body 
below the groin. Press in the hollow just below the 
groin, about two-thirds of the way from the hip-bone to 
the middle line of the body. Double the thigh against 
the abdomen, and bend the leg on to the thigh, with 
the knotted cord in position. 

223. Bleeding from the Stomach and Lungs. — Blood 
that comes from the lungs is bright red, frothy, or 
"soapy." There is rarely much; it usually follows 
coughing, feels warm, and has a salty taste. 

Bleeding from the lungs is a grave symptom. Per- 
fect rest and quiet must be insisted upon. Bits of ice 
should be eaten freely. Loosen the clothing, keep the 
shoulders well raised, and the body in a reclining posi- 
tion. 

Blood from the stomach is not frothy, has a sour 
taste, and is usually dark colored, looking some like 
coffee-grounds. It is larger in quantity, and apt to be 
mixed with food. Do the same as before, except keep 
the person flat on the back instead of in a reclining 
position. 



266 YOUNG FOLKS' PHYSIOLOGY 

224. Bruises, Cut and Torn Wounds. — A bruise 
is a familiar sight. It is a wound of the soft tissues, 
caused by blows. It is more or less painful, followed 
by discoloration due to the escape of blood under the 
skin. A black eye, and a lip or finger hurt by a base- 
ball, are familiar examples of this sort of injury. 
Soak the injured part in ice-cold-water cloths at first, 
and, after the pain is easier, soak the parts in water 
hot as can be borne. If the cuts are small, clean the 
parts, bring the edges together, and stick them with 
plaster. 

When wounds are made with ragged edges, such as 
those made by broken glass and splinters, more skill is 
called for. Every bit of foreign substance must be got 
rid of first. Wash the parts clean with warm water, 
bring the torn edges together, and hold them in place 
with strips of plaster. Do not cover such a hurt all 
over with plaster, but leave plenty of room for the 
escape of matter. 

Wounds made from toy-pistols, percussion-caps, and 
rusty nails, if neglected, often lead to serious results 
from blood-poisoning. Cloths wrung out in cold water 
may be enough, but often a hot flaxseed poultice is 
needed for several days. Keep such wounds perfectly 
clean. 

225. The Pernicious Use of Alcoholic Liquors in 
Accidents and Emergencies. — When an accident 
or sudden illness occurs, people, otherwise very sen- 
sible, are often beset with the idea that brandy or 
whiskey is the great cure-all for all emergencies. They 
do not know what to do, but they want to do something. 



SIMPLE MATTERS OF EVERY-DAY HEALTH 267 

And so they are prone to give the sick or injured person 
a liberal dose of strong drink. It is so common a practice 
that it has passed into common speech as a joke. 

Remember this : on such occasions, alcoholic liquors 
are not only unnecessary, but actually harmful. They 
injure the patient, mislead the doctor, and interfere also 
with the proper treatment of the case. Any simple, 
hot drink will answer every purpose. 

CARE OF THE SICK-ROOM. 

226. Hints for the Sick-room. — The sick-room 
should be the lightest and most pleasant room in the 
house. Some one of the family may be taken sick in 
the attic, or some inconvenient room. If possible, and 
especially if there is a prospect of a long illness, at 
once get a more suitable room ready. 

Take away all extra carpets, upholstered furniture, 
heavy curtains, etc. A clean floor, with a few rugs to 
deaden the footsteps, is much better than a woollen 
carpet. Carpets, extra clothing, etc., only absorb the 
impurities, and help keep the room foul. 

Let the room be accessible to sunlight and fresh air 
It is generally best to shade the room somewhat in cer- 
tain diseases, yet take the time to let in all the sun- 
light possible consistent with comfort. Sunlight and 
fresh air are often more efficient helps than drugs. Be- 
sides, they cost nothing but a little painstaking and 
common sense. Pains must be taken to protect the 
patient from any noise which may disturb him, such as 
the noise of passing steam and horse cars, heavy teams, 
and playing children. 



268 YOUNG FOLKS' PHYSIOLOGY 

Give the sick-room plenty of sweet, fresh air. With 
a little pains, any room may be supplied with pure air. 
If you cannot do anything else, cover the sick person 
all over with extra bed-clothes, open the windows and 
doors, and fan out the bad air. Be sure and avoid 
draughts of cold air. Have a thermometer, and keep 
the temperature as the doctor directs. 

Do not allow a kerosene-light, with its flame turned 
down, to burn through the night. A close room with 
such odor for a whole night is enough to make a 
well person sick. If there is no gas, either use the 
lamp as usual, and put it, carefully shaded, in an adjoin- 
ing room, or, better still, use a sperm candle for a 
night-light. 

Keep a sick-room neat and trim. Remove at once 
all offensive matters. Never allow such things to 
remain for a moment in the room. In many diseases, 
especially scarlet-fever, diphtheria, putrid throat, con- 
sumption, etc., use pieces of old linen instead of hand- 
kerchiefs, and burn them as soon as they are used. 
Carelessness or ignorance in this matter often spreads 
contagious disease. 

Change the clothes of the bed and of the patient 
quite often. Do not let such clothing be put away 
in a closet with others. Put them to soak at once in 
boiling water, with some disinfectant added if neces- 
sary. Do not make a great show of bottles of medi- 
cines, spoons, glasses, etc., carefully spread out on the 
bureau or table. Keep all such things, except such as 
are absolutely necessary, in an adjoining room. 

To a patient not used to sickness, a formidable array 



SIMPLE MATTERS OF EVERY-DAY HEALTH 269 

of drugs and sick-apparatus is apt to be discouraging. 
Some simple thing, like an orange, a tiny bouquet of 
favorite flowers, and one or two playthings, may take 
their place. 

Never get behind the door, in a corner, or in an 
adjoining room, and whisper. It will fret a well per- 
son, to say nothing of its hurtful effects upon a sufferer 
whose nerves may be sensitive to the faintest noise. 

Whatever must be said, say it openly and aloud. 
How often a sudden turn in bed, or a quick glance of 
inquiry, shows that whispering is doing harm ! 

If the patient is in his right mind, answer his ques- 
tions plainly and squarely. It may not be best to tell 
all the truth, but nothing is gained trying to avoid a 
straightforward reply. 

Do not deceive sick people. Tell what is proper or 
safe to be told, promptly and plainly. If a physician is 
employed, carry out his orders to the very letter, as 
long as he visits you. Make a note of his directions 
on a slip of paper. Make a brief record of exactly 
what you do, the precise time of giving medicines, 
etc. 

This should always be done in serious cases, and by 
night-watchers. Then there is no guess-work. You 
have the record before you in black and white. All 
such things are valuable helps to the doctor. 

Above all, let there be cool, wise heads, willing 
hands, loving hearts, and a deal of common sense on 
the part of the helpers in the sick-room ; and a thank- 
ful submission, and a reasonable patience to endure, in 
the sick person. 



270 YOUNG FOLKS PHYSIOLOGY 

POISONS AND THEIR ANTIDOTES. 

227. Poisons in General. — Poisons of various kinds 
are quite generally used in the trades, and kept about 
the house and premises as medicines, as disinfectants, 
for killing insects and animals, and for many other pur- 
poses. People are often careless about them, and leave 
them almost anywhere, wrapped in a piece of paper, or 
in some unlabelled bottle, even in the cupboard, or on 
a shelf about the shed or stable. 

Children either mistake them, or are urged by some 
playmate to swallow them. All of us are too apt to seize 
a bottle or package hastily, and, "before we think," have 
swallowed a dose of some poison. The many fatal ac- 
cidents due to drinking carbolic acid by mistake is a 
familiar example of how stupid or careless people may be. 

All poisons should always be put in bottles care- 
fully labelled, and the word " POISON" should be 
plainly printed in large letters directly across the label. 
Fasten the cork firmly to the bottle by wire picture- 
cord, or copper wire, twisted into a knot at the top. 
This wire would certainly prevent a person from 
mistaking, in the dark, carbolic acid, oxalic acid, etc., 
for some favorite medicine. 

Poison should never be kept in the same place with 
medicines or other bottled preparations used in the 
household. Put them in some secure place, and under 
lock and key. 

Another very simple rule is, never to use the con- 
tents of any package or bottle unless we know exactly 
what it is. Do not guess at it, or take any chances, 
but destroy it at once. 



SIMPLE MATTERS OF EVERY-DAY HEALTH 27 1 

Poisons are often taken when medical help, espe- 
cially in the country, cannot be had at short notice. 
Poisons do their work rapidly. Something must be 
done, and that at once and in earnest. The stomach 
must be emptied as speedily as possible. Make a 
quart of warm soapsuds. Force the sufferer to gulp it 
down, a cupful at a time. Run the finger "down the 
throat," and hasten the vomiting. 

A good emetic is made by putting a heaping table- 
spoonful of ground mustard into a pint of water. 
Drink a cupful every ten minutes until vomiting is 
produced. Stir up a handful of powdered alum in a 
cupful of molasses, and swallow this, a tablespoon- 
ful every ten minutes. 

Be in right good earnest about it, and do not waste 
time to see if the poisoned person likes such heroic 
treatment. Vomiting will not do any harm, and the 
poison may destroy life in a few minutes. 

228. Different Kinds of Poison. — For convenience, 
let us arrange the most common poisons into different 
classes. 

Some are acids, like the oil of vitriol ; others are 
alkalies, like lye. 

• Some are irritant mineral poisons, like arsenic or sugar 
of lead ; while others are vegetable poisons, like aconite 
and James town weed. 

We can easily remember the general plan of treat- 
ment for each special class of the more common poisons. 

229. Acid Poisons. — Sulphuric acid (oil of vitriol), 
nitric acid (aqua fortis), and muriatic acid (spirits of 
salt) are in common use in certain workshops, and oc- 



272 YOUNG FOLKS' PHYSIOLOGY 

casionally used in the household. These are caustic 
mineral acids, that rapidly burn and destroy the living 
tissues. 

Give an alkali. Swallow large quantities of strong 
soapsuds, chalk, tooth-powder, soda or saleratus-water, 
magnesia, or lime-water. Scrape off the whiting from 
the wall, or dig out a piece of plaster. Put them into 
large quantities of water, and swallow the mixture. 
Follow this treatment with some mild, soothing tea 
made of flaxseed or Irish moss. 

Oxalic acid is often mistaken for granulated sugar or 
Epsom salts. For an antidote, use chalk, whitewash, 
plaster, etc., as before. 

Carbolic acid in solution is very commonly used about 
the house. It is a highly dangerous poison, and gen- 
erally fatal. Provoke vomiting by giving large quan- 
tities of soapsuds and sweet-oil mixed together. Fol- 
low with large draughts of oil or milk. Give very 
large doses of Epsom salts. 

230. Alkaline Poisons. — The common alkalies taken 
as poisons are ammonia, or hartshorn, potash, and 
soda, usually dissolved, and often in the form of lye. 
Horse-liniments and other liniments generally contain 
ammonia, and are often taken by mistake. Alkalies 
burn the lining-membranes rapidly and severely. 

Give acids. Drink vinegar freely. Lemon-juice may 
be used. Take large quantities of sweet-oil, linseed-oil, 
and castor-oil. 

231. Metallic Poisons. — Arsenic is a white, sweetish 
powder, used to kill rats. It is occasionally taken 
by mistake. Paris green is a form of arsenic used 



SIMPLE MATTERS OF EVERY-DAY HEALTH 273 

by farmers. Arsenic is also found in ratsbane and fly- 
powder. 

Provoke vomiting at once. Take large quantities of 
milk, the whites of eggs, flour and water, or oil and 
lime-water. A good antidote for arsenic is dialyzed 
iron, which can be bought at any drug-store. It should 
be given freely, in tablespoonful doses, followed by a 
strong solution of salt and water. 

In sugar of lead poisoning, provoke vomiting, and give 
Epsom salts. In copper poisoning by "blue vitriol" and 
"verdigris," give milk or white of eggs, followed by 
flaxseed-tea. 

Children sometimes eat the phosphorus from matches. 
This poison acts slowly, and there is time enough to 
get medical help. Give plenty of magnesia, chalk, or 
whiting, but no oil. 

232. Narcotic Poisons. — The various forms of 
opium are often taken by mistake, or in an overdose. 
The narcotic effects of the following preparations are 
due to opium ; laudanum, paregoric, morphine, Dover's 
powder, Godfrey's cordial, McMunn's elixir, most 
cholera-mixtures, and many of the so-called " soothing- 
sirups " and " drops." 

Brisk emetics must be given until they act thoroughly. 
Give plenty of hot, strong coffee without milk or sugar. 
Keep the patient awake, and do not allow him to fall 
into a deep sleep. Dash cold water over the head and 
shoulders, and slap the skin briskly with wet towels or 
with a slipper. Medical help must be called at once. 

Among other narcotic poisons occasionally taken 
without a knowledge of their poisonous character, 



2 74 YOUNG FOLKS PHYSIOLOGY 

especially by children are aconite, hemlock, deadly night- 
shade, Jamestown weed, monkshood, and toadstools. Use 

essentially the same treatment as in opium-poisoning. 

233. Other Poisons. — Alcoholic liquors are some- 
times taken in sufficient quantities to endanger life at 
once. 

Give a brisk emetic, and stimulate with frequent 
doses of a mixture made of a teaspoonful of the aromatic 
spirits of ammonia, or even ammonia- water, added to a 
glass of hot water. 

Certain kinds of fish act sometimes as poisons to 
certain people, such as eels, crabs, mussels, etc. Fresh 
pork and other fresh meats occasionally act as a mild 
poison. Canned goods of a cheap grade sometimes act 
in the same way. Induce vomiting with some brisk 
emetic, and afterwards give a dose of castor-oil. 

For the sting of hornets, wasps, bees, etc., apply a 
pad of cloth soaked in a solution of carbolic acid, am- 
monia, or spirits of camphor. Crowd the barrel of a 
watch-key deep down on the hurt, to remove the sting 
of the insect. 

DISEASES THAT SPREAD. AND DISINFECTANTS. 

234. How the Air may be Poisoned. — We have 
learned in the chapter on Respiration (chap, ix.), that 
the air may be poisoned by the products of respira- 
tion, and other useless or injurious matters thrown off 
from healthy human bodies. We have shown the bane- 
ful effects of long-continued exposure in an atmosphere 
laden with these impurities. 

N .v, in like manner, the air may be poisoned at cep 



SIMPLE MATTERS OF EVERY-DAY HEALTH 275 

tain times and places by the products of respiration and 
bodily emanations of diseased persons. Thus, in cer- 
tain diseases, called contagions, organic matters are 
thrown off from the persons of the sick, which tend to 
reproduce themselves in some way in the bodies of 
other persons. 

Such diseases as small-pox and scarlet-fever are ex- 
amples of severe and contagious diseases ; while whoop- 
ing-cough, measles, and mumps are contagious, but less 
harmful. 

Again, the air may be poisoned with the foul gases 
arising from the rapidly decomposing contents of cess- 
pools, sewers, and privy-vaults. This poisoned air is 
popularly called sewer-gas. 

The living particles, or "germs," of such diseases as 
typhoid-fever and dysentery, are believed to be con- 
tained, or developed, in the discharges, both from the 
stomach and bowels of persons suffering from these 
diseases. Diphtheria and typhoid-fever are believed to 
be due, oftentimes, to the decomposition of the contents 
of cesspools and sewers. 

Finally, the air may be poisoned by the decomposi- 
tion of organic matters in the ground, and drawn into 
the house in various ways. Thus, there seems to be a 
connection between malarial fever and bad drainage. 
Certain low, damp soils are especially productive of 
consumption. 

235. Disinfection. — With our present knowledge, it 
is not possible to get rid of the germs of disease after 
they are once fastened in the body. We are able, how- 
ever, to a certain extent, to destroy them after they 



276 YOUNG FOLKS' PHYSIOLOGY 

leave the body through the emanations and excreta of 
diseased persons. 

This destruction of the poisons of infectious and con- 
tagious diseases is called disinfection, and the means 
used are called disinfectants. 

We must remember that disinfection cannot compen- 
sate for the want of cleanliness, nor of ventilation. 
Those things which destroy bad smells are not necessa- 
rily disinfectants, and disinfectants do not necessarily 
have an odor. 

236. What Disinfectants to use. — It is our aim to 
speak only of those which can be relied upon, and can 
be easily bought in sufficient quantities, even in our 
smaller villages, at little cost. There are many kinds 
of patented disinfectants, bearing some high-sounding 
name, and sold at a high price, which are of no more 
practical worth than sulphur and copperas, properly 
used. 

It is of the utmost importance, therefore, to know 
the comparative value of disinfectants, and the most 
effective methods of using them. It might be a serious 
mistake, to confound deodorizers — which simply kill 
the odor of disease — with disinfectants, which are 
believed to kill the germs of disease ; and equally 
so to employ a powerful disinfectant in an ineffective 
way. 

Thus, carbolic acid, so much used in the sick-room, 
disinfects what it touches, but does not disinfect the 
air. It is a somewhat costly preparation, and acts 
more effectively in combination with white vitriol and 
copperas. Simply to make outbuildings or a sick- 



SIMPLE MATTERS OF EVERY-DAY HEALTH 2^ 

room smell strong of carbolic acid, does not disinfect 

them. 

The following disinfectants are the most useful : — 
(i) Roll-sulphur or brimstone, for fumigation ; 

(2) Sulphate of iron, or copperas, — also called green 
vitriol, — used in the proportion of one and one-half 
pound to the gallon of water, for sewers, cesspools, 
etc. ; 

(3) Sulphate of zinc, — called white vitriol, — and 
common salt, dissolving about four tablespoonfuls of 
the zinc, and two of the salt, to one gallon of water, 
for clothing, bed-linen, etc. 

237. How to use Disinfectants. — The following 
practical suggestions for the use of disinfectants and 
the management of contagious diseases, were prepared 
for the National Board of Health by a committee rep- 
resenting some of the ablest physicians and sanitarians 
in the country. 

1. In the Sick-room. — The most available agents are fresh 
air and cleanliness. The clothing, towels, bed-linen, etc., 
should at once, on removal from the patient, be placed in a 
pail or tub of the zinc solution, boiling-hot if possible, be- 
fore removal from the room. 

All discharges should either be received in vessels contain- 
ing copperas solution, or, when this is impracticable, should 
be immediately covered with copperas solution. All vessels 
used about the patient should be cleansed with the same 
solution. 

Unnecessary furniture, especially that which is stuffed, 
carpets and hangings, when possible, should be removed 
from the room at the outset : otherwise, they should remain 
for subsequent fumigation and treatment. 



278 YOUNG FOLKS' PHYSIOLOGY 

2. Fumigation. — Fumigation with sulphur 1 is the only 
practicable method for disinfecting the house. For this pur- 
pose, the rooms to be disinfected must be vacated. Heavy 
clothing, blankets, bedding, and other articles which cannot 
be treated with zinc solution, should be opened and exposed 
during fumigation, as directed below. 

Close the rooms as tightly as possible ; place the sulphur 
in iron pans supported upon bricks ; set it on fire by hot 
coals, or with the aid of a spoonful of alcohol, and allow the 
room to remain closed for twenty-four hours. For a room 
about ten feet square, at least two pounds of sulphur should 
be used ; for larger rooms, proportionally increased quan- 
tities. 

3. Premises. — Cellars, yards, stables, gutters, privies, cess- 
pools, water-closets, drains, sewers, etc., should be frequently 
and liberally treated with copperas solution. The copperas 
solution 2 is easily prepared by hanging a basket containing 
about sixty pounds of copperas in a barrel of water. 

4. Body and Bed Clothing, etc. — It is best to burn all arti- 
cles which have been in contact with persons sick with con- 
tagious or infectious diseases. Articles too valuable to be 
destroyed should be treated as follows : — 

Cotton, linen, flannels, blankets, etc., should be treated 
with boiling-hot zinc solution, introducing piece by piece, 
securing thorough wetting, and boiling for at least half an 
hour. 

1 The burning of sulphur produces an irrespirable gas. The person who 
lights the sulphur must, therefore, immediately leave the room, and, after the 
lapse of the proper time, must hold his breath as he enters the room to open the 
windows, and let out the gas. 

After fumigation, plastered walls should be whitewashed, the woodwork well 
scrubbed with carbolic soap, and painted portions repainted. 

2 Put copperas in a pail of water in such quantity that some may constantly re- 
main undissolved at the bottom. This makes a saturated solution. To every 
privy or water-closet use about one pint of the solution night and morning. 



SIMPLE MATTERS OF EVERY-DAY HEALTH 279 

Heavy woollen clothing, silks, furs, stuffed bed-covers, beds, 
and other articles which cannot be treated with the zinc solu- 
tion, should be hung in the room during fumigation, pockets 
being turned inside out, and the whole garment thoroughly 
exposed. Afterward they should be hung in the open air, 
beaten, and shaken. 

Pillows, beds, stuffed mattresses, upholstered furniture, 
etc., should be cut open, the contents spread out, and thor- 
oughly fumigated. 1 Carpets are best fumigated on the floor, 
but should afterward be removed to the open air, and thor- 
oughly beaten. 

1 The cutting open of stuffed articles may seem unnecessary, but it is not. The 
poison of contagious diseases may cling to such stuffs with great tenacity for 
years, and must be destroyed before they are fit to be used again. 

" Contagious diseases are often caught at the funerals of those who have died of 
them; and the sanitary code of New York City forbids a public funeral of any 
person who has died of small-pox, diphtheria, scarlet-fever, yellow-fever, or Asi- 
atic cholera. It is better to limit the attendance at such funerals to as few as 
possible." — Dr. Tracy's Handbook of Sanitary Information. 



28o YOUNG FOLKS' PHYSIOLOGY 



CHAPTER XVI 

PRACTICAL EXPERIMENTS 

238. Why we should make Experiments. — To get 

a thorough mastery of the elementary principles of 
anatomy, physiology, and hygiene, it is not enough 
simply to study the text. 

Just as in chemistry and physics, a series of practical 
experiments is made, both by the teacher and the pupils, 
so should " physiology," as it is popularly called, be 
illustrated on the same general principles. Geology 
would certainly be a dry study without suitable speci- 
mens to illustrate the text-book. 

So, in the study of physiology, it is almost impossible 
to get an intelligent idea of the text, and that practical 
knowledge which is so desirable, without the aid of 
specimens and experiments. 

Whatever we see with our eyes, feel with our fingers, 
and do with our hands, in the matter of experiment and 
illustration, however simple and homely, is of far more 
worth than merely studying the printed page. It is 
more like hard work, to be sure ; but laziness is a poor 
excuse in this or in any other branch of science. 

239. Importance of making Experiments. — It is 
plain that any series of experiments arranged for use 
in our common schools must be somewhat crude. We 
must take many things for granted. The observation 



PRACTICAL EXPERIMENTS 28 1 

and experience of medical men, and the experiments of 
the physiologist in his laboratory, must be relied upon 
for important data not otherwise easily obtained by 
young students. 

Because we cannot make our experiments with such 
accuracy and detail as in other branches of science, it 
by no means follows that we cannot use experiments in 
the common schools. The simplest experiments be- 
come, in the hands of the enthusiastic and skilful 
teacher, of the greatest value and interest. Pupils soon 
gain a far better knowledge, and keep up a livelier 
interest in the subject, if, as we have just said, they see 
with their own eyes, and handle with their own hands, 
that which serves to illustrate the subject. 

This method of instruction rivets the attention, and 
keeps alive the interest, of the young pupil ; in fact, it 
is the true method of cultivating a scientific habit of 
study. Hence the following experiments, however 
simple and rude the apparatus, become important helps 
towards gaining a more thorough knowledge of this im- 
portant branch of study. 

240. General Plan of Study. — We should depend 
for this part of our study upon five sets of illustra- 
tions : — 

(1) The Skeleton and Manikin. 

(2) Experiments on the Person. 

(3) Study of Physiological Charts. 

(4) Blackboard Diagrams and Sketches. 

(5) A systematic series of simple Experiments performed by 
the Teacher and the Pupils. 



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purpose of experiment and observation. The success oi 
this part of the work will depend upon the skill, tact, 
and common sense of both teacher and pupils. How 
much time and effort it is best to devote to this part of 
J the study depends upon the age and capabilities of the 



PRACTICAL EXPERIMENTS 283 

class. There is no better way to get an accurate 
and thorough knowledge of the more essential and prac- 
tical points of anatomy. 

243. Study of Charts. — A set of physiological charts 
is very desirable, and should be secured for every-day 
reference in the schoolroom. 

244. Blackboard Diagrams and Sketches. — The 
pupil should be trained to make and to copy sketches 
and diagrams in his note-book, and repeat them at 
stated intervals on the blackboard. Such sketches may 
be somewhat rude, and there will be a great contrast in 
the work of different pupils ; but this is of little 
account. 

The teacher is advised to make for himself a series of 
diagrams, on a suitable scale for the blackboard, on 
sheets of manila paper, and have them bound, and hung 
up for easy reference in the schoolroom, somewhat in 
the same way that reading-charts are now made. 
These sketches may be used to illustrate the text, and 
then copied by the pupil in his note-book or on the 
blackboard. 

245. A Series of Simple Experiments. — By all 
means, depend upon a systematic series of rude, homely 
experiments, such as have been suggested in this 
chapter. They are simply suggestive. Do not merely 
copy them, but contrive others equally good. 

In most schools, the cost is an important matter. 
Accordingly, we have limited most of the experiments 
to such as can be done with cheap, homely, and simple 
apparatus, most of which can be picked up about the 
house, the market, and the village store. 



284 YOUNG FOLKS' PHYSIOLOGY 

All these experiments should be performed both by 
the teacher and each member of the class. It is not 
enough for the student to sit still, and see the teacher 
do them. Pupils should be encouraged to get together 
the material, and repeat some of the experiments on 
Saturday, or during a holiday. Clubs of three or four 
friends will find it both profitable and interesting to 
work together on a spare evening. 

246. Hints and Helps. — When specimens of bones, 
joints, dissections, etc., are carried into the school- 
room, the utmost pains must be taken to keep every- 
thing neat and clean. Use large plates, platters, 
saucers, tissue-paper, with plenty of pins, needles, clean 
towels, and napkins. Cover every part except what it 
is necessary to show. Keep everything covered until 
the proper time comes. 

Every little detail must be arranged before the reci- 
tation begins. If the fingers get soiled, remove all 
traces at once. Strict attention to all these little 
matters may make the difference between success and 
failure. 

If the school does not own a microscope, secure the 
loan of one, if possible, for a few weeks. No one ever 
forgets the first look at a drop of blood, or the circula- 
tion of blood in a frog's foot, as revealed by the micro- 
scope. 

Glass slides ready for the microscope, and illustrating 
every part of the body, can be bought or ordered 
in any large city, of dealers in microscopic or scientific 
apparatus. 



PRACTICAL EXPERIMENTS 



285 



EXPERIMENTS ON THE BONES 

[Chapter II. Page 13.] 

Experiment 1. To show the Gross Structure of Bone. — 
Saw lengthwise in two the bones of a sheep's leg, or a calf's 
leg, including the knee-joint end. Save one-half. Boil, 
scrape, and carefully clean the other half. Note in the boiled 
half the compact and spongy parts, shaft, etc. 

Note on the other half, after trimming off the flesh, the 
pinkish-white look of the bone, the marrow and its tiny specks 




Fig. 85. — Blackboard Sketch. Side view of the Lower Jaw. 



of blood, etc., — in other words, the difference between the 
fresh (live) bone, and an old, dry one (dead) easily found for 
the purpose. 

2. To show the Minute Structure of Bone. — Show the 
minute structure of bone by specimens of bone mounted on 



286 YOUNG FOLKS' PHYSIOLOGY 

glass slides, and sold for microscopic use, costing only 
a few cents. If a microscope cannot be had, let each 
pupil draw a blackboard-sketch of the microscopic look of 
bone. 

3. To show the Animal Part of Bone. — Get a chicken's 
leg, or a sheep's rib. Scrape and clean. Put one of the 
bones to soak into a mixture of four tablespoonfuls of muri- 
atic acid to one pint of water. A wide-mouthed bottle is the 
best thing to hold it ; next, an earthen bowl. 

Soak from five days to a week. It can now be bent, 
twisted, and even tied into a knot, showing that the earthy 
matter has been dissolved. 

4. To show the Earthy, or Mineral, Part of Bone. — Get a 
large soup-bone from the table. Roast it on a bright, hot 
coal-fire for three hours. Do it carefully, and get a good 
specimen free from bone-black. The animal matter has now 
been burned out. The earthy part, a white, brittle mass, is 
now seen, showing every outline of the bone. Crumble parts 
of it between the fingers, and otherwise experiment upon 
it. 

Study of the Skeleton. — Let us now proceed to study the 
skeleton in two ways, — first, by means of the mounted skele- 
ton prepared for such use ; second, by the examination of the 
skeleton or bones of our own person, or that of a friend. 

Every important part of the body can be mapped out with 
the fingers. Whether a skeleton or a chart is used, this drill 
on the living body is essential to a practical knowledge of 
anatomy. Let a boy stand before the class ; and, as the 
teacher points out on his person the location of the various 
bones and bony landmarks of the body, each one of the class 
should stand, and do the same on his own person. 

The amusement of the thing will soon wear away, then 
settle down to hard drill. Do it thoroughly. Crowd the 



PRACTICAL EXPERIMENTS 



287 



fingers deep down into the flesh, and trace the outline of the 
bones (the collar-bone and shoulder-blade, for example) very 
carefully. Do it all with neatness, tact, and a due regard for 
the feelings of all concerned. 

Use both the common and the scientific name for many of 
the bones. Drill thoroughly until all become perfectly famil- 
iar with the location of the most important and accessible 
bones and landmarks of the body. 

5. The Skeleton. — Its Study as a Whole. — Point out head, 
trunk, and limbs ; long, short, flat, and round bones. Note 
how some bones protect 
certain parts, how others 
are built for use, beauty, 
and protection. Other 
such points will readily 
suggest themselves. 

Do the same on the 
person, so far as it is con- 
venient. Use the chart for 
the same purpose. 

6. Parts of the Skeleton. 
— The Head. — Drill on 
the skeleton for the bones 

of the head; the same on FlG . 86. - blackboard sketch. u PP er 
the person. Use the chart. end of the Thigh-bone, showing how the 

c , , . , girders of bone are arranged to sustain great 

7. bhOW hOW the DOneS weight and ren der the bone less liable to 

of the skull are jointed ; fracture. 

the sutures ; the plates of bones ; the rough surfaces for the 
attachment of muscles ; holes and notches for arteries and 
nerves. If nothing better can be had, get a part or the 
whole of some animal's skull from the market, or even from 
the fields. 

8. The Trunk. — Note the various bones as before. 




SHAFTS 

Fig. 86. — Blackboard Sketch. 



288 



YOUNG FOLKS PHYSIOLOGY 



Trace and count each rib and vertebra. Make a special 
study of the spine. 1 

9. The Upper Limbs. — The upper arm, fore-arm, hand. 
Experiment exactly the same as before. Every part can be 
carefully traced on the person. 

10. The Lower Limbs. — Thigh, lower leg, foot. Experi- 
ment as before. 

11. Repair of the Bones. — Ask some pupil who has broken 
his arm or collar-bone some time previously, to show how 

well the broken parts have united ; the 
healing-cement at place of union, etc. 

12. Joints. — Get a part of a calf's or 
sheep's leg at the market. Open up 
the joint carefully, and carry it fresh 
and moist into the class for experiment. 

Note the sticky joint-oil ; synovial 
fluid ; glistening surfaces of the ends of 
the bones ; the gristle ; cartilages ; place 
where tendons, ligaments, and muscles 
are fastened. 

13. To show the Various Kinds of 
Joints. — Illustrate on the person the 
fixed and movable joints ; ball and 
socket ; hinge ; pivot joints. Try the 

fig. s 7 .- blackboard principal joints of the body, and see 

Sketch. The arrangement just how much and what motion they 
of bones at the Knee Joint. , 

J have. 

14. The Ligaments. — In cutting open the joints, note the 
tough, firm, and gristly bands, which help hold the bones to- 
gether. These are the ligaments. Try to tear or wrench them 

1 Some parts of this experiment, as well as others, should be reserved for 
the privacy of one's room. It is a most useful exercise to review the day's 
work after undressing for the night. 




PRACTICAL EXPERIMENTS 289 

off from the bone, to see how firm and tough they are. Care- 
fully dissect one or two ligaments in whole or in part, leaving 
one end fastened to the bone, to illustrate their action. 

15. Bony Landmarks of the Body. — Go over the skeleton 
or person, and locate with the fingers certain important 
"bony landmarks," as the angle of the lower jaw, elbow-end 
of the ulna, wrist-end of the radius, highest point (acromion) 
of scapula, lower end of breast-bone, upper end of tibia ; 
lower end of fibula, etc. 

Other landmarks will suggest themselves. This will make 
an excellent review-exercise. 



EXPERIMENTS WITH THE MUSCLES 

[Chapter III. Page 42.] 

Experiment 16. To show the Gross Structure of Muscles. 
— Get about one-half of a pound of lean corned beef, a 
strip with the fibres running all one way. Have it thoroughly 
boiled. Let it cool, and press it with the weight of several 
flat-irons. Put it on a firm board or table, and pick it in 
pieces with two darning-needles. 

Note the connective tissue, the larger muscular fibres. 
Pick with the needles until the fibres are too small to manage. 
Continue with a hand magnifying-glass. Examine the tiniest 
bit of fibre with a microscope. 

17. Again, boil a beef shin-bone for several hours. Note 
as before the coarse structure of the muscular fibres. Cut 
away the muscles and dissect, to examine the fibrous tissue, 
fat tissue, ligaments, and cartilage, or gristle. 

18. To show how Muscles contract and relax. — Get the 
lower part of a sheep's leg at the market, with the foot or 



29O YOUNG FOLKS PHYSIOLOGY 

hoof still on ; dissect with a sharp knife one or more muscles, 
leaving the insertion. Even if it is roughly done, it is no 
matter ; for the fibres can be carefully smoothed into place 
with a knife-blade, stained with carmine ink. and made to 
iook natural as life. 

Better make the dissection a week or so ahead of time, and 
let the parts harden a little in dilute alcohol. Then stain. 
and get it ready just at the time needed. The contraction 
and relaxation of muscles are thus roughly shown. 

19. Use your own biceps and triceps muscles to show 
how muscles contract and relax, and how they oppose each 
other in action. 

Repeat the same with other muscles, as the flexors and 
extensors of the fingers and toes, of the leg, etc. 

20. To show the Structure and Action of Tendons. — Take 
some of the material from the previous dissection, and 
examine the tendons. Get the leg of a fowl at the market, 
to show the tendons which make the toes bend. Get the 
butcher to save the hoof of a calf or sheep with one end of 
the tendon of Achilles still attached. Dissect it. and test its 
strength. 

21. Make a study of the tendons on your own person. 
Grasp the powerful tendons of the hip-muscles under the 
knee, of the lower leg near the ankle, of the fore-arm at 
the wrist. 

Experiment with white braid tied on the tips of the fingers. 
and fastened on the arm, to show how the tendons of the 
arm work. Tie a ribbon tightly round the wrist to imitate 
the annular ligament, and note how differently the tendons 
act when they are under it or above it. 

22. To show how Muscles use the Bones as Levers. — First 
use a blackboard-pointer, broom-handle, or any other familiar 
object as a lever. Practise using it as a lever of the three 
different kinds, until the principles are familiar. 



PRACTICAL EXPERIMENTS 29I 

Now illustrate on the person. Vary this experiment in 
many ways. Lift a book on the toes, by the fingers, on the 
back of the hand, by the mouth by bending over to reach it, 
raise the book from a chair, and rest it on the head. 

Fasten a piece of braid to the neck of a bottle. Now tie 
one end to various parts of the body, as the middle of the 
arm, the fore-arm, the end of the fingers and foot, etc. ; 
raising the bottle each time, and explaining exactly what 
kinds of levers are used, and also what kinds of muscles are 
used, — flexors or extensors. 

23. To locate some Important Muscles. — Locate and de- 
scribe them on the chart. Do the same as far as it is possi- 
ble and convenient on the person. 

Clutch tightly such muscles as the biceps, deltoid, great 
pectoral, muscles of the calf of the leg, etc. Run the fingers 
over the location of others. 

Drill until the location and duty of the more important 
muscles become familiar. 

24. Muscular Landmarks. — Use the chart, skeleton, and 
person to locate the most important muscular landmarks, as 
the origin and insertion of the biceps ; tendon of Achilles ; 
aunular ligament ; edges of the great pectoral and biceps ; 
flexor cords of the forefinger, etc. 

This may be made an admirable drill-exercise. 



EXPERIMENTS ON FOOD AND DRINK 

[Chapter V. Page 70.] 

A series of most useful experiments may be made on the 
subject of food and drink. The common articles of diet 
greet us on every hand. It should be our object to under- 
stand the principles which underlie the matter of daily food. 



292 YOUNG FOLKS PHYSIOLOGY 

We should become familiar with the principal substances 
contained in the three great classes of foods. We can do 
this by exhibiting specimens, and by experiment. 

Specimens of the various cereals, starches, sugars, oil, etc., 
should be shown, which have been carefully collected, and 
kept for class-use in empty morphine or quinine bottles 
bought at the drug-store. Small radish or pickle bottles are 
good enough. Each specimen should be neatly labelled with 
its exact name. 

Many interesting facts can be brought out about the 
practical use of these substances as foods, when we are able 
to touch, taste, smell, and see the substances themselves. 

Experiment 25. To show Albumen. — The albumens are 
all rich in one or more of the following organic substances : 
albumen, casein, nbrine. gelatine, gluten, and legumen. Boil 
an egg hard. The white is albumen hardened by heat (see 
Exper. 27). 

26. To show Casein. — Pour some liquid rennet, vinegar, 
or a little weak acid, into some milk. A whitish substance 
(the curd) separates from it. This nitrogenous substance is 
casein, the chief constituent of cheese. 

27. To show Fibrine. — Take a piece of lean meat, and 
wash it thoroughly in water, squeezing and pressing it well 
in a lemon-squeezer. A whitish, string}- mass is obtained, 
which is the jibrine. The albumen is dissolved in the water. 
Boil the water after the meat has been washed. The heat 
coagulates the albumen. 

28. To show Gelatine. — Boil a bone a long time. Most 
of the animal matter will be dissolved. The substance thus 
dissolved is gelatine } 

1 You may have seen your mother boil calves' feet to make jelly for the sick- 
room. The familiar substances glue and size are simply gelatine obtained by 
boiling the hoofs, horns, skins, etc., of animals. 



PRACTICAL EXPERIMENTS 293 

29. To show Gluten. — Put a handful of flour into a mus- 
lin bag, and squeeze it well in a basin of water. The water 
becomes milky ; while a sticky, yellowish- white substance 
remains in the bag. This sticky substance is the gluten. 
Allow the water to stand, and the starch settles at the bottom 
in a white powder. 

30. To show Legumen. — Boil a few peas or beans in the 
pod, until they become a sticky, pulpy mass. This is the 
nitrogenous principle called legumen, and resembles the white 
of an egg and the gluten of flour. Nearly every kind of 
vegetable is rich in this flesh-forming material. 

31. To show the Starches. — Specimens of the more com- 
mon kinds of foods rich in starch should be shown, and 
passed round the class in bottles. Potato, rice, sago, arrow- 
root, tapioca, corn-flour, etc., may be used for illustration. 

The presence of starch is easily proved. Boil a small 
quantity of flour, rice, bread, potato, or arrowroot in a little 
water, in a test-tube. Add a drop or two of the tincture of 
iodine, and the mixture will turn blue. 

32. To show the Sugars. — Cane-sugar is familiar as cook- 
ing and table sugar. Various specimens should be shown, 
including varieties of molasses, in two-ounce vials. To show 
grape-sugar, get some raisins, and pick out a handful of the 
little white grains. Get a cent's worth of milk-sugar at the 
drug-store. 

In starch and sugar, the oxygen and hydrogen are combined in just 
the proportions necessary to form water. Sulphuric acid reacts upon 
either starch or sugar to remove the oxygen and hydrogen ; and carbon, 
or charcoal, is left behind. Hence, the name carbo-hydrates, or hydrates 
of carbon, is given to this class of substances. There are three groups, 
the sugars proper, the glucoses, and the starches and gums. In a rough 
way, we may speak of them as carbon dissolved in water. 

33. Take several wine-glasses. Put some thin starch paste 
into the first, and several varieties of sugar into others. 



294 YOUNG FOLKS PHYSIOLOGY 

Pour in carefully down the side of each glass a little sul- 
phuric acid. The mixtures will turn black. The acid has 
precipitated the charcoal. Stir a little charcoal in another 
wineglass full of water, and pour in acid as before. It 
remains black : no change has taken place. 

34. By heat, starch is converted into a kind of sugar. 
This is called dextrine. This is a gummy substance, soluble 
in water, and is used on the back of postage-stamps. 

Touch the tip of the tongue to the back of a postage-stamp, 
and the sweet taste will be noticed. Dextrine is sold in the 
shops under the name of " British gum." 

35. To show the Various Kinds of Fats and Oils. — Show 
specimens of fats that are solid at ordinary temperatures, 
such as beef-suet, mutton-suet, lard and butter. 

Liquid fats are commonly called oils. The two principal 
kinds used as food are olive-oil and cod-liver oil. The first 
is obtained from the fruit of a tree, and the second from the 
livers of the cod and the haddock. 

36. Simple Experi?nents to show that Milk is a Model Food. 
— Milk is rightly called a compound food, since it is com- 
posed of at least five kinds of food-substances. Take some 
milk "fresh from the cow," and place it in a tall, narrow 
glass vessel, and allow it to stand for several hours. A 
quantity of cream rises to the top. Cream is the milk-fat. 
It is simply made up of tiny bags of fat, each of which has 
a covering of curd. 

By churning the cream about a short time, the covering is 
broken, and the little lumps of fat unite to form the yellow 
solid called butter. Now skim off the cream : what remains 
is called skim-milk. Add a teaspoonful of vinegar, weak 
acid, or liquid rennet, to the skim-milk. Solid whitish lumps 
of curd will be seen separating from a watery fluid called 
whey (see Exper. 83). 



PRACTICAL EXPERIMENTS 295 

We have now divided the milk into three parts, — cream, 
curd, and whey. Cream is the fat ; curd is the casein, or 
nitrogenous part, which, when pressed and dried, is called 
cheese ; and whey is milk-sugar and mineral matter dissolved 
in water. 

These simple experiments show that milk contains flesh- 
forming, bone-making, and heat-giving materials, and that 
it contains these in the right proportions, especially for 
children. 

37. To show Water, a?id the Minerals. — Water is too 
familiar a food for experiment. If water could be easily 
obtained from some iron or sulphur springs, it would be 
interesting to compare the taste with specimens of hard and 
soft water from the neighborhood. 

The mineral matter left from Experiment 4 shows the 
various kinds of lime and potash. An egg-shell is a familiar 
example of carbonate of lime. Various kinds of salt (forms 
of soda) can be obtained from any grocer. 

The white of an egg contains a little sulphur. Leave a 
silver spoon in it for a short time, and the sulphur will 
blacken it. 



EXPERIMENTS WITH ALCOHOL 
[Chapter VI. Page 8i.] 

Experiment 38. Alcohol, and how it looks. — Get at the 
drug-store a four-ounce white-glass bottle, and let the drug- 
gist fill it for you with the best alcohol. Have it tightly 
corked, and properly marked with a label gummed on the 
bottom of the bottle. 

To remember : Alcohol is a thin, colorless liquid, which 
looks like water. 



296 



YOUNG FOLKS PHYSIOLOGY 



39. To show how Alcohol burns. — Turn a little alcohol 
into an old-fashioned fluid lamp. Light it, and note the 
character of the light and the heat. Put a white saucer or 
plate closely down on the flame for a few minutes. 

Note that the alcohol burns without soot, giving little 
light but great heat. 

Suggestion. — If a fluid lamp is not easily obtained, use a small kero- 
sene lamp without the chimney. A lamp good enough for simple experi- 
ments can be made out of a common mucilage bottle, using the hollow 
handle of the metallic brush for the wick. A 
piece of a bean-blower run through the cork of 
an empty horse-radish bottle, using a rolled piece 
of kerosene- wick for the wick, will also provide 
the necessary apparatus for an alcohol lamp. 

40. To show that Alcohol and Water 
unite readily, with a Slight Decrease of 
Volume. — Use a test-tube which will 
contain one fluid ounce (eight teaspbon- 
fuls). Drop in thirty drops each of 
alcohol and water. Gum a strip of white 
paper four inches long and one-fourth of 
an inch wide to the side of the test-tube, 
bringing the lower end on a level with 
the sixty drops of fluid in the tube. 
Have the strip of paper marked off into inches and one- 
eighths of an inch. 

Drop water carefully into the tube until exactly two inches 
have been added, as shown on the graduated paper ; then drop 
in alcohol until exactly two inches more have been added. 
Shake the tube carefully, taking care not to spill any of 
the fluid. 

Note that the alcohol and water unite with a slight de- 
crease of volume. 




Fig. 88. 



PRACTICAL EXPERIMENTS 297 

41. To show the Great Attraction of Alcohol for Water. — 
Tie tightly some thin membrane (like the coverings of the 
sausages sold in the markets) across the mouth of a bulb 
test-tube. Place the test-tube (bulb downward) in a goblet 
or beaker. Fill the bulb with alcohol, and pour pure water 
into the goblet or beaker (Fig. 95). 

The alcohol will soon rise in the tube, thus proving that 
alcohol has such a liking for water that it has caused the 
water to filter through the membrane. 

42. lb show the Origin of Alcohol in Fermented Liquors. 
— Take a common glass fruit-jar which will hold one pint. 
Fill the jar one-half full of water, and add molasses until it 
is of a deep-brown color. Ad-d a teaspoonful of yeast or 
one-half of a yeast-cake. Cover so as to admit some air, and 
keep at a temperature of 70° F. for a day or two. 

Note the result: The mixture has the odor of alcohol. 
What has happened ? Why, the yeast (called a " ferment ") 
has changed the sugar of the molasses to alcohol. The pro- 
cess of changing is called "fermentation." 

43. Take as before a common glass fruit-jar which will 
hold one pint. Fill it one-half full of sweet cider. Allow 
the liquid to stand exposed to warm air. After a few days, 
shake the jar and it will be found that the liquid has the 
peculiar odor of alcohol. Very minute ferments have 
changed the sugar of the sweet apple-juice to alcohol. If 
the liquid should be left exposed to the air, it would, after 
a time, change to vinegar, which is known by its sour, acid 
taste. 

44. Use a fruit jar as before. Fill it one-half full of sweet 
or unfermented wine. Continue the experiment as ex- 
plained in Experiment No. 43. 

45. Take two wide-mouthed bottles holding one pint 
each. Be able to connect the two bottles A and B, as shown 



298 



YOUNG FOLKS PHYSIOLOGY 



in Fig. 96. Let a glass tube run from bottle B. and empty 
into a glass jar (C). Use a little putty or sealing-wax to srop 
any leaks made by the tubing running through the corks. 

Fill the bottle A about one-half full of molasses. Add 
one yeast-cake which has been dissolved in water. Fill the 
bottle with water, and shake vigorously. Fill the bottle B 
nearly full of water. 

Keep the apparatus in a warm room for two or more days : 
an even temperature of 75 ° to 8o° F. will do. 

The pupil will note that the fluid in the bottle A soon 
begins to "work."" and that a substance called the lees set- 




Fig. So. 

ties to the bottom of the bottle. The water in Bottle B will 
pass up the tube and over into the glass jar C. Note also 
that there is a change in the smell of the liquid. By the 
change that has taken place a gas has been formed which 
has forced the water in B over into the glass jar. This 
change is called fermentation. 

46. To show the Presence of Alcohol in Distilled Liquors. — 
Heat hard cider or sherry wine in a large-sized test-tube over 
an alcohol lamp. Run a piece of glass tube, bent at right 
angles, through a cork which fits the test-tube ; let the other 



PRACTICAL EXPERIMENTS 



299 



end of the tube be fitted into the cork of a wide-mouthed 
bottle which is set into a basin of cold water to condense the 
steam. 

The resulting liquid has a marked odor and taste. It is 
stronger than the fermented liquid. This process is called 
"distillation," and the resulting liquid, "distilled liquor." 



Fig. 90. 



47. Pour one-half of a pint of hard cider into a common 
tin coffee-pot. Fasten a piece of rubber tubing to the spout. 
Have the other end of the tubing run into a wide-mouthed 
bottle sunk into a basin of cold water. Cloths wrung out 
in ice-water may be wrapped round the bottle. Heat the 
cider in the coffee-pot by an alcohol lamp, placed as shown 
in Fig. 97. Do not allow the cider to boil. 

Note that the color and odor of the resulting liquor differ 
from the color and odor of the hard cider. A stronger 
liquor has been produced by this process. This process is 
called distillation. The stronger liquor has been separated 
from the water. It may be necessary to re-distil the result- 
ing liquor several times before a liquor is found pure enough 
to burn. 



3O0 YOUNG FOLKS' PHYSIOLOGY 

48. To show the Effect of Alcohol on Albumen. — Place the 
white of an egg in an empty quinine or horse-radish bottle. 
Pour in some strong alcohol. Stir with a spoon or glass rod. 

Note that the alcohol hardens, or coagulates, the albumen ; 
in other words, the alcohol has such a liking for the warer of 
the albumen, that it withdraws it. leaving it hard. 

49. Repeat the same experiment, using dilute alcohol (one- 
half alcohol and one-half water). 

50. Place in the same kind of a bottle as before a small 
strip of raw beefsteak. Add strong alcohol, and let mixture 
be set aside for a few days. 

Note that the meat seems hard. The alcohol has coagu- 
lated the albumen of the meat. The alcohol withdraws the 
water of the fresh, elastic, muscular tissue, leaving it tough 
and hard. 

51. Squeeze a piece of fresh beef in a lemon-squeezer 
over a wide-mouthed bottle. Pour in a little water: stir it 
until well colored with blood. Add strong alcohol. Set 
aside for several days. 

Note that the liquid is full of white particles. The alcohol 
has coagulated the albumen of the blood. 

52. Repeat the last two experiments, using dilute alcohol. 
Note the result after a few days. 

Take two bottles, into one of which some days before 
were placed weak alcohol and a piece of beef : into the 
other, pure alcohol and beef. Take a piece of fresh beef, 
and you will find that it is as strong as a whip-cord. Now 
observe these pieces in the bottles. They are dry and 
brittle. They break like a piece of suet. 

53. To show the Action of Alcohol on Pepsin. — Take two 
ordinary wide-mouthed bottles holding from a gill to half a 
pint (A and B). Put into the first bottle five grains of pep- 
sin and two or three ounces of lukewarm water. Make it 
acid with twenty drops of strong muriatic acid. 



PRACTICAL EXPERIMENTS 301 

Do exactly the same thing with the second bottle, except 
add three tablespoonfuls of alcohol. Set the bottles in any 
convenient place sufficiently warm (near a stove or on a 
mantel near a warm smoke-pipe) to keep the contents of 
the bottles at about blood-heat. 

After ten hours, note the changes, if any. The pepsin is 
precipitated in the form of white, stringy particles in the 
bottle containing alcohol, while the other bottle shows no 
change ; in other words, the alcohol has precipitated the 
pepsin of the artificial gastric juice. 

54. Prepare the bottles exactly as before. To the bottle 
A add two teaspoonfuls of finely minced albumen. Put 
it in a warm place, as in Experiment No. 53. Shake very 
often. The pepsin will begin to act upon the albumen, 
gradually softening it. In actual digestion, albumen is 
thus made ready to soak through the moist lining of the 
stomach. 

Do exactly the same thing with the second bottle (B) 
except add three tablespoonfuls of strong alcohol. Expose 
the bottle to heat, as before. After ten hours, note the result. 
It will be seen that alcohol has coagulated the albumen in 
bottle B. 

55. Repeat Experiment No. 54. Instead of the white 
of an egg, add a teaspoonful of finely cut, cooked, and lean 
beefsteak or corned beef. In the bottle A the meat will be 
more or less dissolved or partially digested in twenty-four 
hours. In the bottle B the effect of the alcohol will be to 
make the meat seem hard. In short, the alcohol has coagu- 
lated the albumen of the meat. 

56. Repeat Experiments 53 and 54. Instead of alcohol, 
use strong beer, whiskey, and rum, to show the action of 
the more dilute forms of alcohol upon the various types of 
albumen. 



302 YOUNG FOLKS PHYSIOLOGY 

57. Repeat Experiment 41. Instead of plain water, add 
one-quarter of a teaspoonful of common salt to the given 
amount of water. This saline solution will represent, in a 
general way, the plasma of the blood. The alcohol will rise 
in the tube, as in Experiment 41. Now, if we use very dilute 
alcohol (one part of alcohol to ten parts of water), we find 
that the alcohol in the tube falls. 

In other words, when alcohol is sufficiently dilute, it will 
go towards the fluid representing the plasma of the blood. 

58. To show how Alcohol coagulates the Blood. — Get your 
market-man to carry a clean wide-mouthed fruit-jar to the 
slaughter-house, and let the butcher fill it with fresh blood. 
Add at once to the fresh blood a heaping tablespoonful of 
Epsom salts dissolved in a coffee-cup full of water. This 
strong saline solution will prevent the formation of a clot. 
Keep the whole mixture in a cool place, and do not shake 
it. Draw off two ounces of the mixture, and add to it a pint 
of water. Set it aside. It remains clear. 

Dilute the same amount of the mixture with a pint of 
water, and pour in a few tablespoonfuls of strong alcohol. 
Note that the blood is soon coagulated. 

59. To show the Effect of Alcohol on the Blood Corpuscles. 
— Squeeze the end of the forefinger and pierce the skin 
quickly with a fine needle, drawing a drop of blood. 
Examine it carefully with a microscope. Note the little 
corpuscles, their shape, and how they are arranged. 

Add the tiniest drop of alcohol. The corpuscles shrink 
and become of a different or irregular shape. The alcohol 
has coagulated the albumen of the corpuscles. 

60. To show the Effect of Alcohol on the Circulation of the 
Blood. — Stretch the web of a frog's foot over a hole in a 
thin board, as fully directed in Experiment No. 98. Do this 
carefully to avoid giving pain to the frog. 



PRACTICAL EXPERIMENTS 303 

Note carefully the circulation of blood through the very 
small blood-vessels. 

Now put on the web a drop of dilute alcohol, and note the 
result. The little blood-vessels seem to stretch and to allow 
the blood corpuscles to pa,ss through more rapidly. 

The alcohol has weakened the nerves which regulate the 
flow of blood in the capillaries, thus allowing more blood to 
flow through them. 

61. Repeat the preceding experiment. Instead of dilute 
use strong alcohol. Note that the capillaries soon shrivel, 
and the flow of blood stops. 

The alcohol in this case has paralyzed the nerves which 
control the capillaries. The tiny blood-vessels now contract, 
and stop the flow of blood. 



EXPERIMENTS ON DIGESTION 
[Chapter VII. Page 92.] 

62. To show the Anatomy of Certain Organs, and Parts of 
Organs^ of Digestion. — Have each pupil examine his own 
mouth, and also that of some friend. Note the Hps, tongue, 
hard palate, soft palate, uvula, tonsils, and upper part of the 
gullet. 

63. The Teeth. — Get a specimen of each kind of tooth if 
possible. A dentist-friend will give you what you need. 
Use a very fine saw to saw a perfect molar in two lengthwise. 
If need be crack the tooth with a hammer. 

Note its structure in a general way, — its crown, body, 
cusps, roots, enamel, dentine, pulp-cavity, etc. 

64. Make a blackboard-sketch of a tooth on a large scale, 
using colored crayon to make plain the various parts of a tooth. 



304 



YOUNG FOLKS PHYSIOLOGY 



CROWN/ 



65. Tc show the Difference of Teeth in Various Animals. — 
Get, if possible, specimens of teeth of the more familiar 
animals, 1 as the cat, dog, rat, squirrel, etc. Compare them 
with the specimens of human teeth. 

66. With the help of a mirror, let each pupil locate his 
own teeth. Note the incisors, eye-teeth, bicuspids, molars, 

and " wisdom " teeth if any. In the 
same way, note the teeth of some 
schoolmate. 

67. Locate as near as possible the 
position of each salivary gland. Press 
on the part of the cheek opposite the 
second small molar of the upper jaw, 
and notice the increased flow of saliva. 
The appearance of saliva is familiar. 

68. To show Location of Other Or- 
gans of Digestion. — Make a black- 
board diagram, in the rough, of the 
organs of digestion, beginning at the 
cardiac end of the stomach, after hav- 
ing studied the digestive organs on 

Fig. 91. — Blackboard ^ e c h ar j- 
Sketch. Section of a Tooth. 

Map out on the person in a very 
general way the location of the stomach, small intestines, 
and the colon, liver, pancreas, and spleen. The location of 
the stomach and liver is especially important. 

69. To show how the Wall of the Stomach looks. — The 
wall of the pig's stomach resembles the human stomach. Get 
from the market a piece of a pig's stomach. Cut off bits 
of it, and examine it thoroughly. Scrape off the inner or 
mucous coat with the edge of a very sharp knife. 

1 No stress is laid in this book upon the subject of "comparative anatomy." 
Many valuable points can be given orally by the painstaking teacher. For refer- 
ence, consult Mivart's Lessons on Elementary Anatomy. 




°AT\& 



coat^ 



PRACTICAL EXPERIMENTS 305 

Use a magnifying-glass ; find the openings of the gastric 
tubes. Pick with fine needles, and note the muscular coats. 
Contrast the pig's stomach with that of a cow's by examining 
a piece of tripe. 

70. To make the Saliva flow. — Think of some favorite 
article of food (both at the time you are hungry and when 
you are not), and note the flow of saliva. Push a lead-pencil 
or the finger to and fro in the mouth several times, and note 
the flow of saliva. 

Chew an oyster-cracker, and note carefully how it is 
moistened with saliva. Grind up several crackers rapidly in 
the mouth. Note how difficult it is to swallow, or even chew, 
when there is little saliva. 

71. The importance of the saliva in favoring the movements 
of chewing may be illustrated by the experiment of wiping 
the inside of the mouth perfectly dry with a towel or handker- 
chief ; when it will be found almost impossible to move the 
jaws until the saliva is again secreted in sufficient quantity 
to moisten the surface of the tongue, cheeks, and gums. 

72. The importance of the saliva as a solvent may be shown 
by wiping the upper surface of the tongue quite dry with a nap- 
kin, and then placing a small quantity of powdered sugar upon 
it. The sugar will be found to be as destitute of taste as so 
much sand ; whereas in its ordinary moist condition the tongue 
perceives the taste of sweet substances very distinctly. 

This experiment also illustrates the fact that the termina- 
tions of the nerves of taste can be affected only by sub- 
stances brought in contact with them in the liquid state. 

73. To show the Action of Saliva o?i Starch. — Chew 
slowly a piece of fresh bread. 1 Note how sweet it tastes after 

1 Chew pieces of the brown crust of the bread. It is quite sweet, and readily 
dissolves ; because, exposed to more heat than the rest of the loaf, the starch has 
been changed into dextrine before the bread left the over?. Hence, crust and toast 
are favorite articles of food, especially with old people. 



306 YOUNG folks' physiology 

it is well wet with the saliva. Do the same with a mouthful 
of paste made of pure arrowroot (almost pure starch), made 
with boiling water, and allowed to cool. 

- - Take three test-tubes. Into test-tube No. 1, half full 
of cold water, add some half a dozen drops of the arrow- 
root paste ; now put one of Fehling's Test-Tablets. 1 Mix 
thoroughly, and boil over a spirit-lamp. There is no turbid 
brick-red deposit to show that there is sugar in the starch 
(arrowroot). 

75. Put several teaspoonfuls of saliva into test-tube No. 
2. Dilute it with water. Add a test-tablet, mix thoroughly, 
and boil. There will be a violet color, but no brick-red 
deposit to show the presence of sugar in the saliva. 

76. Take test-tube No. 3, and put a few drops of the 
starch paste into a teaspoonful of saliva, and fill the test-tube 
half-full of water. Put the mixture away for ten minutes 
in a warm place. Now add a test-tablet. Mix and boil. 
A turbid brick-red deposit will be thrown down, showing 
that sugar is present, due to the action of the saliva on 
starch. 

77. To show the Action of Gastric Juice on Albumen. — 
Take an ordinary four-ounce bottle with as wide a mouth as 
convenient. Put into it the following: Pepsin in scales 
(Fairchild's), 2 one grain, and four tablespoonfuls of luke- 
warm water. Make it acid with ten drops of strong muriatic 

1 These tablets have been used of late as a convenient means by which physi- 
cians may test for sugar. It is simply an easy way to use the test usually made 
with a solution of caustic potash and blue vitriol. 

2 It is not at all necessary to go through die long process of getting pepsin 
from a pig's stomach. Pure pepsin, obtained from the stomach of the pig, 
is now ""^ by dealers for medical use; and the necessary amount can be 
bought of a good druggist for a few cents. Use only pure pepsin in the 
experiments. The student b advised to use Fairchild's "Pepsin" and "Ex- 
tract of Pancreas- ,, 



PRACTICAL EXPERIMENTS 2>°7 

acid. Add two teaspoonfuls oF finely minced egg-albu* 
men. 1 

Set the mixture in any convenient place sufficiently warm, 
as in a basin of warm water, near the stove, or on the mantel 
near the warm smoke-pipe, to keep the contents of the bottle 
at about " blood-heat." 2 Shake every few minutes. As 
soon as the whole mixture becomes of a proper temperature, 
the pepsin will begin to act upon the albumen; and it may 
be seen to be gradually softened and digested. 

This dissolved mass is now in a condition to readily soak 
through the moist lining of the stomach, and is known as 
" peptone." 

78. Repeat the same experiment, using half a teaspoonful 
of finely cut, cooked, and lean beefsteak or corned beef in- 
stead of the white of an egg. The meat will be more or less 
dissolved, or partially digested, in twenty-four hours. 

This is only a crude way to show the action of gastric 
juice on meat-albumen. 

79. Get some freshly drawn blood. Whip it with twigs. 
Pull off the collected fibrine, and wash it carefully in clean 
water. Save this in dilute alcohol, and use it as a handy 
albumen for digestive experiments. Repeat as directed in 
Experiments 77 and 78. 

80. To show the Action of Bile on Fat. — Shake up a 
little sweet-oil and water. " Oil and water will not mix," 
as the saying goes. Get the butcher to bring you a small 

1 The albumen or the white of an egg is taken as the type of albumen in 
a naturally pure state, and is well adapted to illustrate the peptonizing action 
of the gastric ferment. It should be first made ready as follows : Separate the 
white of a hard-boiled egg, and rub it through a coarse sieve, so as to divide 
it into small particles. 

2 In these experiments on digestion, the temperature should never be below 
blood-heat, and never allowed above a point at which fluids can be easily 
borne by the mouth. 



308 YOUNG folks' physiology' 

bottle of bile (ox-gall), or, better still, ask him to bring the 
gall-bladder itself. Cut it open, and bottle the contents. 
Shake up some oil with bile, and a creamy mixture called 
an " emulsion " results. 

8 1. To show the Action of Pancreatic Juice upon Oils or 
Fats. — Put two grains of Fairchild's Extract of Pancreas 
into a four-ounce bottle. Add half a tablespoonful of warm 
water, and shake well for a few minutes ; then add a table 
spoonful of cod-liver oil ; shake vigorously. 

A creamy, opaque mixture of the oil and water (called an 
" emulsion ") will result. This will gradually separate upon 
standing, the pancreatic extract settling in the layer of water 
at the bottom. It will again form an emulsion when shaken. 

82. To show the Action of Pancreatic Juice on Starch. — 
Make a smooth starch paste, just as the laundress does in 
starching her clothes. Put two tablespoonfuls of this paste 
into a goblet or tumbler, and, while still so warm as to just 
be borne by the mouth, stir into it two grains of the Extract 
of Pancreas. The starch paste will at once become thinner, 
and gradually changed into soluble starch, in a perfectly 
fluid solution. 

83. To show the Action of Pancreatic fuice upon the Albu- 
minous Ingredients (casein) of Milk. — Into a four-ounce 
bottle put two tablespoonfuls of cold water ; add one grain 
of Fairchild's Extract of Pancreas, and as much baking-soda 
as can be taken up on the point of a penknife. Shake well, 
and add four tablespoonfuls of cold, fresh milk. Shake 
again. 

Now set the bottle into a basin of hot water (as hot as can 
be borne by the hand), and let it stand for about forty-five 
minutes. While the milk is digesting, take a small quantity 
of milk in a goblet, and stir in ten drops or more of vinegar. 
A thick curd of casein will be seen (see Exper. 36). 



PRACTICAL EXPERIMENTS 3O9 

Upon applying the same test to the digested milk, no curd 
will be made. This is because the pancreatic ferment (called 
trypsin) 1 has digested the casein into " peptone," which does 
not curd. This digested milk is therefore called " peptonized 
milk." 2 

84. Study of the Liver. — The whole of a liver is rather an 
awkward and bulky thing to handle ; but it is a good plan 
to get a sheep's liver, and devote a little time to its gross 
anatomy. Take pains to get the liver with the gall-bladder 
unbroken. Having once secured a fine specimen, it may be 
kept for future use in dilute alcohol. 

85. To illustrate the Principle of Absorption. — The manner 
in which absorbent vessels suck in juices may be illustrated 
in a general way as follows : Take a glass tube, and tie a 
piece of bladder, in the form of a small bag, at the end of 
it ; pour some mucilage into it, and then plunge the end into 
a cup or glass containing water. 

In a few moments the mucilage in the tube will begin to 
rise, and the water in the glass will sink ; because, being 
more dense than the water, it draws it in through the bladder, 
and will continue to do so until they are equal. Again, if 
we put mucilage into the glass, and fill the tube with water, 
the water will fall in the tube until they become of the same 
thickness. 

It is on this principle that the absorbent vessels suck in 
liquids which are thinner than what they previously con- 
tained. 

1 The active principle of the saliva which acts upon starch is often spoken of 
as ptyalin, in order to distinguish it from the starch-digesting principle of the 
pancreatic juice. Both have the same action upon starch. Experiment 57 will 
also illustrate the action of saliva. 

2 Infants, especially those brought up on artificial foods, often suffer from ill 
digestion, " summer complaint," and other intestinal troubles during hot weather. 
Partially digested, or peptonized milk is often found to be of the greatest ser- 
vice at such times. 



3io 



YOUNG FOLKS PHYSIOLOGY 



EXPERIMENTS ON THE HEART AND THE CIRCU- 
LATION 

[Chapter VIII. Page 122.] 

Experiment 86. — Tie a string tightly round the finger, 
and pierce the tip of it with a needle. The blood runs freely, 
is red and opaque. Put a drop of fresh blood on a sheet of 
clean white paper, and note that it looks yellowish. 

87. Put a drop of fresh blood on a clean white plate. 
Cover it with an inverted goblet or sauce-plate. Take off 
the cover in five minutes, and the drop has set into a jelly- 
like mass. Breathe into the goblet several times to moisten 

it, and replace it over the blood. 
Take it off in half an hour, and 
a little clot will be seen in the 
watery serum. 

88. To show the Blood-Clot. — 
Carry a clean wide-mouthed 
bottle to the slaughter-house. 
A half-pound chloral bottle 
bought at any drug-store is the 
best. A clean horse-radish bot- 
tle will do. Fill it with fresh 
blood. Carry it home with 
great care, and let it stand over 
night. The next day the clot will be seen floating in the 
nearly colorless serum. 

89. To show the Fibrine of the Blood. — Get a wide- 
necked bottle full of fresh blood. A pint or quart fruit-jar 
is the best for this purpose. Beat the blood vigorously for 
five minutes with some dry twigs, and hang them up to dry. 
Let the blood stand until the next day. Note that it has 




Fig. 92. — Blackboard Sketch 
The Heart and its four rooms. 



PRACTICAL EXPERIMENTS 



311 



not clotted. Wash out the twigs thoroughly, and a stringy 
mass of elastic substance will be found hanging to them. 
This is the fibrine. 

90. Take some of the serum saved from Experiment 88, 
and note that it does not coagulate of itself. Boil a little in 
a test-tube over a spirit-lamp, and the albumen will coagulate. 

91. To show that blood is really a mass of red bodies, 
floating in a fluid, which give it the red color. Fill a clean 
white-glass bottle two-thirds full of little red beads, and then 
fill the bottle full of water. At a short distance the bottle 
appears to be filled with a uniformly red liquid. 

92. To show the Blood Corpuscles. — A moderately power- 
ful microscope is necessary to examine 

blood corpuscles. Let a small drop of 
blood (which may be readily obtained 
by pricking the finger with a sharp 
needle) be placed upon a clean slip of 
glass, and covered with a piece of thin 
glass, such as is ordinarily used for mi- 
croscopic purposes. 

The blood is thus spread out into a 
film, and may be examined with the 
microscope. At first the corpuscles will 
be seen as pale, disk-like bodies float- 
ing in the clear fluid. After a time 
they will be observed to stick to each 
other by their flattened faces, so as to form rows. The color- 
less corpuscles are to be seen among the red ones, but 
they are much less numerous. 

93. To show how Blood holds a Mineral Substance in Solu- 
tion. — Put an egg-shell crushed fine into a glass of water 
made acid by a teaspoonful of muriatic acid. After an hour 
or so the egg-shell will disappear, having been dissolved in 




Fig. 93. — Blackboard 
Sketch. The Heart and its 
great Blood-vessels. 



312 



YOUNG FOLKS PHYSIOLOGY 



the acid water. In like manner the blood holds various 
minerals in solution. 

94. To show the Sounds of the Heart. — Locate the heart 
exactly. Note its beat. Borrow a stethoscope from some 
physician. Listen to the heart-beat of some friend. Note 
the sounds of your own heart in the same way. 

95. To find the Pulse. — With your right hand grasp the 
right wrist of a friend, pressing with three fingers over the 
radius. Press three fingers of your right hand over the radius 
in the left wrist, to feel your own pulse. With the aid of a 

watch, count the rate of 
your own pulse per min- 
ute. Do the same with a 
friend's pulse. 

96. To show how the 
Pulse ??iay be studied by 
press i?ig a Mirror over the 
Radial Artery. — Press a 
small piece of looking- 
glass upon the wrist over 
the radial artery in such 
a way that with each 
pulse-beat the mirror may 
be slightly tilted. If the 
wrist be now held in such a position that sunlight will 
fall upon the mirror, a spot of light will be reflected on the 
opposite side of the room, and by its motion upon the wall 
will be shown the movements of the artery as the pulse-wave 
passes through it. — Bowditch's " Hints for Teachers of 
Physiology." 

97. Dissection of a Sheep s Heart. — Get a sheep's heart 
with the lungs attached, as the position of the heart will be 
better understood. Let the lungs be laid upon a dish so 




Fig. 94. — How the Pulse may be studied by 
pressing a Mirror over the Radial Artery. 



PRACTICAL EXPERIMENTS 313 

that the heart is uppermost, with its apex turned towards 
the observer. 

The line of fat which extends from the upper and left side 
of the heart downwards and across towards the right side, 
indicates the division between the right and left ventricles. 

Examine the large vessels, and, by reference to the text 
and illustrations, make quite certain which are the aorta, 
the puhnonary artery, the superior and inferior vence cava, 
and the pulmonary veins. 

Tie variously colored yarns to the vessels, so that they 
may be distinguished when separated from the surrounding 
parts. 

Having separated the heart from the lungs, cut out a por- 
tion of the wall of the right ventricle towards its lower part, 
so as to lay the cavity open. Gradually enlarge the opening 
until the chorda tendinece and the flaps of the tricuspid valve 
are seen. Continue to lay open the ventricle towards the 
pulmonary artery until the semilunar valves come into view. 

The pulmonary artery may now be opened from above 
so as to display the upper surfaces of the semilunar valves. 
Remove part of the wall of the right auricle, and examine the 
right auriculo-ventricular opening. 

The heart may now be turned over, and the left ventricle 
laid open in a similar manner. Notice that the mitral valve 
has only two flaps. The form of the valves is better seen 
if they are placed under water, and allowed to float out. 
Observe that the walls of the left ventricle are much thicker 
than those of the right. 

Open the left auricle, and notice the entrance of the pul- 
monary veins, and the passage into the ventricle. 

The ventricular cavity should now be opened up as far as 
the aorta, and the semilunar valves examined. Cut open 
the aorta, and notice the form of the semilunar valves. 



314 YOUNG FOLKS PHYSIOLOGY 

98. To show the Circulation in a Frog's Foot. — In order 
to see the blood circulating in the membrane of a frog's foot 
it is necessary to firmly hold the frog. For this purpose 
obtain a piece of soft wood, about six inches long and three 
wide, and half an inch thick. At about two inches from one 
end of this, cut a hole three-quarters of an inch in diameter, 
and cover it with a piece of glass, which should be let into 
the wood, so as to be level with the surface. Then tie up 
the frog in a wet cloth, leaving one of the hind-legs outside. 
Next, fasten a piece of cotton to each of the two longest 
toes, but not too tightly, or the circulation will be stopped 
and you may hurt the frog. 

Tie the frog upon the board in such a way that the foot 
will just come over the glass in the aperture. Pull carefully 
the pieces of cotton tied to the toes, so as to spread out the 
membrane between them over the glass. Fasten the threads 
by drawing them into notches cut in the sides of the board. 
The board should now be fixed by elastic bands, or by any 
other convenient means, upon the stage of the microscope, 
so as to bring the membrane of the foot under the object- 
glass. 

The flow of blood thus shown is indeed a wonderful sight, 
and never to be forgotten. The membrane should be occa- 
sionally moistened with water. 

Care should be taken not to occasion any pain to the frog. 



EXPERIMENTS ON THE LUNGS AND BREATHING. 

[Chapter IX. Page 142.] 

Experiment 99. To locate the Lungs. — Mark out the 
boundaries of the lungs by "sounding" them; that is, by 
percussion as it is called. It simply means, to put one fin- 
ger across the chest or back, and to give it a quick, sharp 



PRACTICAL EXPERIMENTS 315 

rap with another. Note where it sounds hollow ; that is, is 
resonant. This experiment can be done only in a very 
crude way. 

100. Borrow a stethoscope, and listen to the respiration 
directly below the collar-bones. Note the difference in in- 
spiration and expiration. 

1 01. Get a sheep's lungs, with the windpipe attached, 
from a butcher or marketman. Ask for the heart and lungs 
all in one mass. Take pains to examine the specimen first, 
and pay only for a good one. Parts are apt to be hastily 
snipped or mangled. 

102. Examine the windpipe. Note the horseshoe-shaped 
rings of gristle in front, which serve to keep it open. 

103. Examine one bronchus, carefully dissecting away 
the lung-tissue with curved scissors. Follow along until 
small branches of the bronchial tubes are reached. Take time 
for the dissection, and save the specimen in dilute alcohol. 
Put pieces of the lung-tissue in a basin of water, and see if 
they float. 

104. To show how the Lung may be filled with Air. — Take 
the other lung, and tie a glass tube six inches long into its 
bronchus. Attach a piece of rubber to one end of the glass 
tube. Now blow up the lung, and then let it collapse several 
times. When distended, examine every part of it. 

105. To show the Diaphragm. — Dissect a rat or kitten, 
and cut out a section of the body large enough to show the 
diaphragm and its attachments. The parts can be neatly 
held in place by pins and silk threads, and the whole kept 
in dilute alcohol. 

106. To show the Vocal Cords. — Get a pig's windpipe in 
perfect order from the butcher, to show the vocal cords. 
Once secured, it can be kept for an indefinite time in 
alcohol. 



316 YOUNG folks' physiology 

107. To show that the Air we breathe out is warm. — 
Breathe on a thermometer for a few minutes. The mercury 
will rise rapidly. 

108. To show that it is moist. — Breathe on a mirror, or a 
knife-blade, or any polished metallic surface. 

109. To show that the Air we breathe out contains Car- 
bonic Acid. — Put a glass tube into a bottle of lime-water, 
and breathe out into it through the tube. The liquid will 
soon become cloudy, because the carbonic acid of the ex- 
pired air throws down the lime held in solution. 

1 10. To show the Natural Temperature of the Body. — Bor- 
row a physician's thermometer, and take your own tempera- 
ture, and that of several friends, by putting it under the 
tongue, closing the mouth tightly, and holding it there for 
five minutes. 

in. '*'A substitute for a clinical thermometer may be 
readily contrived by taking an ordinary house thermometer 
from its tin case, and cutting off the lower part of the scale 
so that the bulb may project freely. With an instrument 
thus arranged, the pupils may take their own and each other's 
temperature ; and it will be found that whatever may be the 
season of the year or the temperature of the room, the ther- 
mometer in the mouth will record about 99 F. Care must, 
of course, be taken to keep the thermometer in the mouth 
till it ceases to rise, and to read it while it is still in position." 
— Prof. H. P. Bowditch. 



EXPERIMENTS ON THE SKIN 

[Chapter X. Page 161.] 

Experiment 112. To show the Gross Structure of the Skin. 
— Examine your own skin in a general way. Stretch and 



PRACTICAL EXPERIMENTS 317 

pull it, to show how elastic it is. Get some idea of the scarf- 
skin by scraping off some with a sharp knife. 

Note any white scars, liver-spots, etc., on the skin. Exam- 
ine the skin with much care, with the aid of a good magni- 
fying-glass. Note the papillae on the palm of the hand. 

113. Hair and Nails. — Pull a stout hair from the head, 
and examine it carefully with the magnifying-glass. Make 
a similar study of the finger-nails. 

114. The Sweat-glands. — Use a magnifying-glass to study 
the openings of the sweat-glands, especially on the palms of 
the hands. 



EXPERIMENTS ON THE NERVOUS SYSTEM 

[Chapter XI. Page 177.] 

Experiment 115. To show the Brain and Spinal Cord. — 
It is a troublesome matter to dissect out the brain and the 
spinal cord of one of the smaller animals like the rat, rabbit, 
or cat. The back of the animal to be dissected should be 
turned upwards, and the limbs should be securely fastened 
to the top of a small table. 

The skin is removed from the head by making a longitu- 
dinal incision in it, and then turning it back upon each side. 
The muscles upon the sides and back of the skull should 
next be cleared away. A hole may now be made in the top 
of the skull with the point of a pair of scissors, and the bone 
broken away piece by piece, with a pointed pair of nippers, 
until the upper surface and sides of the brain can be seen. 

In the cat, kitten, or rabbit, the cerebral hemispheres do 
not, as in man, cover the cerebellum ; and consequently the 
latter is seen when the brain is viewed from above. 

When the bone has been broken away enough to expose 



3i 



YOUNG FOLKS PHYSIOLOGY 



the sides of the brain, the latter should be carefully raised 
by inserting the tips of the fingers under it on one side, 
and gently pulling. 

Several white cords will thus be seen passing from the 
under surface of the brain to the floor of the skull : these 
are the cra?iial ?ierves. 

To expose the spinal cord, the skin of the back must be 
removed, and the muscles cut away from each side of the 
backbone, as close to the bone as possible ; then, beginning 
at the back of the skull, the spinal canal is to be laid open 
by cutting with the nippers the two sides of each vertebra. 

Care must be taken not to cut or 
tear the spinal cord, or the nerves 
passing off from it. 

When the spinal cord has thus 
been exposed, and the membranes 
which surround it made out, the 
spinal nerves should be examined. 
The brain and spinal cord should 
now be removed, by carefully lift- 
ing them, and cutting off the nerves 
by which they are attached. 

The specimen should now be 
neatly fastened to a thin strip of 
smooth pine-wood, and firmly held 
in place with pins. The whole can 
be kept in alcohol and water. Great patience is necessary 
to make the dissection a success. 

116. To show the Brain. — A sheep's or calf's brain is to 
be preferred, on account of its larger size. Get one fresh 
from the butcher. Pay him to dissect away the skin and 
muscles of the skull, under your direction, and to saw open 
the cranium in a circular direction. Take time, and remove 




Fig. 95. — Blackboard Sketch. 
Showing the Position of the Brain. 



PRACTICAL EXPERIMENTS. 319 

the sawed top with great care, tearing away the dura mater 
from the bones. 

Now cut away enough of this membrane so that the sides 
of the skull can be sawed and torn away, to allow us to lift 
out the brain, with proper dissection, in as perfect a state as 
need be. Put all the torn parts and membranes back into 
place. Put the whole aside to harden for three days in 
alcohol. Now we are ready to study its gross anatomy. 

Note the dura mater, the arachnoid lining it, and the pia 
mater closely attached to the brain. Find the cerebrum, or 
big brain, the cerebellum, or little brain, the medulla, and the 
stumps of the cranial nerves, especially the stumps of the 
optic nerves. The hardened brain should be first examined 
as a whole, and compared with the description given in 
the text, or the pictures of the human brain. 

117. Sensations are referred to the Ends of the Nerves. — 
Strike the elbow-end of the ulna against anything hard 
(" hitting the crazy-bone ") where the ulna nerve is ex- 
posed, and the little finger and the ring-finger will tingle, and 
become numb. 

118. Every Nerve is independent of any Other. — Press 
two fingers closely together. Let the point of the finest 
needle be carried ever so lightly across from one finger 
to another, and we can easily tell just when the needle leaves 
one finger, and touches the other. 

119. One Part of the Body works for the Good of a?iother 
Part. — Tickle the inside of the nose with a feather. This 
does not interfere with the muscles of breathing ; but they 
come to the help of the irritated part, and provoke sneezing 
to clear and protect the nose. 

120. To paralyze a Nerve temporarily. — Throw one arm 
over the sharp edge of a chair-back, bringing the inner edge 
of the biceps directly over the edge of the chair. Press 



320 YOUNG FOLKS PHYSIOLOGY 

deep and hard for a few minutes. The deep pressure on the 
nerve of the arm will put the arm " asleep." causing numb- 
ness and tingling. The leg and foot often "get asleep" by 
deep pressure on the nerves of the thigh. 



EXPERIMENTS ON THE SPECIAL SENSES 

[Chapter XII. Page 210.] 

Experiment 121. — Cross the middle finger over the 
forefinger, and shut the eyes. Hold a marble between the 
tips of the crossed fingers. This experiment will produce 
the impression of there being two marbles. 

122. Shut both eyes, and let a friend run the tips of the 
fingers firs: lightly over a hard, plane surface, then pressing 
hard, and then lightly again, and the surface will seem to be 
hollowed out. 

These two experiments show that we are easily misled, 
even by the sense of touch. It is mainly matter or habit 
and education. 

123. Put a drop of vinegar on a friend's tongue, or your 
own. Notice how the papillae of the tongue start up. 

124. Rub different parts of the tongue with the pointed 
end of a piece of salt or gum-aloes, showing that the back of 
the tongue is most sensitive to salt and bitter substances. 

125. Repeat the same with some sweet or sour substances, 
to show that the edges of the tongue are the most sensitive 
to these things. 

126. Apply the points of a pair of compasses to various 
places on the surface of the body, to show the most sensitive 
spots. 

127. We often fail to distinguish between the sense of 



PRACTICAL EXPERIMENTS 321 

taste and that of smell. Chew some pure, roasted coffee, 
and it seems to have a distinct taste. Pinch the nose hard, 
and there is little taste. Coffee has a powerful odor, but 
only a feeble taste. The same is true of garlic, onions, and 
various spices. 

128. Light helps the sense of taste. Shut the eyes, and 
palatable foods taste insipid. Pinch the nose, close the eyes, 
and see how palatable a teaspoonful of cod-liver oil becomes. 

129. Gently turn the inner part of the lower eyelid down- 




Fig. 96. — Blackboard Sketch. Showing how the Image of an Object is 
brought to a Focus on the Retina. 

wards. Look in a mirror ; and the small " lachrymal point," 
or opening into the nasal duct, may be seen in your own 
eye. 

130. Close the eyelids, and press firmly on to the eyeball 
with two fingers. Note how firm and dense it is to what 
one might imagine. 

131. The Retina is easily tired. — With a hand-mirror 
reflect the sunlight on the white wall, and keep it fixed. 
Look steadily at it for a full minute, and then let it suddenly 
be removed. Its "complementary" color — a dark spot — 
will appear. 

Pin a round piece of bright red paper (large as a dinner- 



322 YOUNG FOLKS PHYSIOLOGY 

plate) ro a white wall by a single pin. Fasten a long piece 
of thread to it, so it can be pulled down in a second. Gaze 
steadily at the red paper. Have it removed while looking 
at it intently, and a greenish spot takes its place. 

132. To illustrate the Action of ike Crystalline Zens. — 
Hold a burning-glass in front of an open window in such a 
way that the image of some object outside will be brought 
to a focus upon a piece of paper. This miniature image 
will be upside down. 

133. The walls of the eyeball of a white rabbit are quite 
transparent. Hold a lighted candle before the cornea. An 
image of the candle will be seen reflected on the retina. 

134. " Remove the front convex lens from a pair of opera- 
glasses, or procure a convex lens with a gradual curve. 
Hold it opposite a window, and place a piece of white paper 
behind it to act as a screen. A small reversed picture of 
the window-frame will appear on the paper. 

" If the paper be moved to a certain distance, varying with 
each lens, the picture will become clear and distinct, yet 
with color-rings about the edges. At that distance from the 
lens the paper is said to be in focus. If the paper be moved 
nearer to, or farther from, the lens, the picture becomes 
blurred, and the paper is said to be out of focus. 

135. " Visit a photographer's studio. Request him to 
point out and name the uses of the essential parts of the 
camera, — the blackened box, the ground-glass screen, the 
lens, the diaphragm, and the apparatus for adjusting the lens 
and the screen to the object Watch him place the camera 
and then work the ground-glass screen into the proper focus. 
When all is ready, put your head under the curtain of the 
camera and study the reversed image depicted on the glass." 
— Cutter's Physiology. 

136. To vibrate the drum-membrane and the little ear- 



PRACTICAL EXPERIMENTS 323 

bones, shut the mouth, and pinch the nose tightly. Try to 
force air through the nose. The air dilates the eustachian 
tube, and air is forced into the ear-drum. The distinct 
crackle, or clicking sound, is due to the movement of the 
ear-bones and membranes. 

137. The Retina is not sensitive wkere the Optic Nerve 
enters the Eyeball. — This is called the "blind spot." Put 
two ink-bottles about two feet apart, on a table covered over 
with white paper. Close the left eye, and fix the right stead- 
ily on the left-hand ink-stand, gradually varying the distance 
of the eye to the ink-bottle. At a certain distance the right- 
hand bottle will disappear ; but nearer or farther than that, 
it will be plainly seen. 

138. Show the same thing in this way : make two black 
spots, with pen and ink, as large as two peas, upon a white 



Fig. 97. — Diagram to show the Existence of the Blind Spot. 

card, about three inches apart, varying the distance as be- 
fore. At a distance of about six inches the " blind spot " 
will be noticed. 

139. Impressions made upon the Retina do not disappear 
at once. — Look steadily at a bright light for a moment or 
two,, and then turn away suddenly, or shut the eyes. A 
gleam of light will be seen for a second or two. 

140. Take a round piece of white card-board the size of 
a saucer, and paint it in alternate rings of red and yellow, 
— two primary colors. Put it on the sewing-machine wheel, 
or glue it to a grindstone, and rotate it rapidly. The eye 
perceives neither color, but orange, — the secondary color. 

141. To note the shadows cast upon the retina by opaque 



324 YOUNG FOLKS PHYSIOLOGY 

matters in the vitreous humor, popularly known as floating 
specks, or gossamer threads, look through a small pin-hole 
in a card at a bright light covered by a ground-glass shade. 

142. Test the eyes of the pupils by a set of Suet/en's test- 
types. The following test-line should be easily read at ten 
feet. Some pupils may be able to read it at a distance of 
eleven or more feet. 

VZBDFHKOS 

143. .72? dissect a?i Eye. — The eyes of a codfish, a sheep, 
or a pig are easily obtained. Put them in the snow over night 
during winter, or freeze them with salt and ice during warm 
weather. They are easier to dissect when frozen. 

Examine one specimen from the outside, however, before 
freezing dulls its bright colors. Saw out a square piece of 
the skull that holds the eye, and see just how it is held in 
place naturally, how the optic nerve enters the orbit, etc. 

Dissect with great care the frozen eye. 

The fat should be dissected off, together with the muscles, 
and the eye cut in half from above downward. This will be 
most easily accomplished by holding the eye between the 
forefinger and thumb of the left hand, upon a slice of turnip 
or potato, and then cutting it between finger and thumb with 
a sharp razor. 

The transparency of the cornea, lens, vitreous humor, and 
also of the retina should be noticed, so as to compare them 
with the same parts when hardened. 

In the posterior portion may be seen, through the trans- 
parent vitreous humor, the entrance of the optic nerve, and 
the blood-vessels which radiate from this point over the 
delicate, transparent retina, the latter spreading like a film 
over the whole of the interior of this half of the eye. 



PRACTICAL EXPERIMENTS 325 

Remove the vitreous humor and the retina, so that the 
brightly colored choroid coat may be seen. 

Within the front half of the eye will be seen a portion of. 
the vitreous humor and the perfectly transparent lens. 

The aqueous humor is best shown by taking an entire 
fresh eye, and cutting through the cornea, when this fluid 
will be seen to spurt out. 

Both transverse and longitudinal sections should be exam- 
ined. The latter are best made by placing the eye upon 
a piece of cork, with the cornea downwards, and then, pass- 
ing the razor through the middle of the optic nerve, cut the 
eye in half. 

When the razor is felt to be in contact with the hardened 
lens, cease to draw it, and finish the section by simply pressing 
it through, otherwise the lens will be drawn out of its place. 

144. Get a sheep's kidney at the market. Study care- 
fully its shape, size, etc., as a whole. Freeze it, if necessary, 
and then cut it in two lengthwise. 

Notice the difference between the inner and the outer 
portions. This is something like the difference in texture 
between the pith and the hard rind of some flower-stems, 
such as the sunflower. 

The outer part is called the cortical part, which means the 
" bark ; " and the inner is called the medullary, or " marrow." 



EXPERIMENTS ON THE THROAT AND VOICE 

[Chapter XIV. Page 280.] 

Experiment 145. To show the Anatomy of the Throat. 
— Study the general construction of the throat by the help 
of a hand-mirror. Repeat the same on the throat of some 
friend. 



326 YOUNG FOLKS' PHYSIOLOGY 

146. To illustrate the Passage of Air through the Glottis. 
— Take two strips of india rubber, and stretch them over 
the open end of a boy's " bean-blower," or any kind of a 
tube. Tie them tightly with thread, so that a chink will be 
left between them. 

Force the air through such a tube with a bellows, or even 
by blowing hard, and a sound will result if the strips are not 
too far apart. The sound will vary in character, just as the 
bands are made tight or loose. 

147. " A very good illustration of the action of the vocal 
band in the production of the voice may be given by means 
of a piece of bamboo or any hollow wooden tube, and a strip 
of rubber, about an inch or an inch and a half wide, cut from 
pure sheet rubber such as is used by dentists for rubber 
dams. 

" One end of the tube is to be cut sloping in two directions, 
and the strip of sheet rubber is then to be wrapped round 
the tube, so as to leave a narrow slit terminating at the 
upper corners of the tube. 

" By blowing into the other end of the tube the edges of 
the rubber bands will be set in vibration, and by touching 
the vibrating membrane at different points so as to check 
its movements it may be shown that the pitch of the note 
emitted depends upon the length and breadth of the vibrat- 
ing portion of the vocal bands." — Dr. H. P. Bowditch. 

148. To show the Construction of the Vocal Organs. — 
Get a butcher to furnish two windpipes from a sheep or a 
calf. They differ somewhat from the vocal organs of the 
human body, but they will enable us to recognize the differ- 
ent parts which have been described, and thus to get a good 
idea of the gross anatomy. 

One specimen should be cut open lengthwise in the middle 
line in front, and the other cut in the same way from behind. 



PRACTICAL EXPERIMENTS 327 



EXPERIMENTS ON MATTERS OF EVERY-DAY 
HEALTH 

[Chapter XV. Page 249.] 

Experiment 149. Imagine a pupil with his fingers or 
ears frost-bitten. Show how friction should be applied. 

150. Poultices. — Bring a small lot of the necessary material 
into the schoolroom, to show exactly how a mustard paste, a 
flaxseed poultice, or any other simple poultice, is made. A 
small poultice four inches square is large enough for the 
experiment. 

Let one or more pupils use the same material, and make a 
number of poultices. 

151. Fainting. — Select several places about the school- 
room, and show exactly how a person should be placed, sup- 
posing he has fainted in a crowded room. Go through every 
detail of treatment in your mind. 

152. Apparent Browning. — Show exactly how artificial 
respiration is done. Let a boy lie on a settee, and illustrate 
the process in every detail. It would be an excellent idea 
for a teacher to meet his boys at their bathing-place, and 
show them in still more detail. 

Let two boys go through the process on a playmate under 
the eye of the teacher, and then others might follow their 
example. 

153. To carry an Injured Person.— Take some one of the 
small boys, and show how he could be carried home or else- 
where in case of injury. 

154. Burns. — Have a small quantity of soda, sweet-oil, 
and lime-water in the schoolroom. Imagine a pupil has 



328 YOUNG FOLKS' PHYSIOLOGY 

burned his arm or hand. Show exactly what is to be done, 
and how. 

155. Foreign Bodies. — A thoughtful teacher can make 
several experiments to illustrate the text. 

156. Experiments on the Matter of treating Cuts and 
Bruises, and of stopping Bleeding. — Let red-pencil marks 
made on the face, arms, fingers, etc., stand for cuts. Apply 
suitable strips of plaster in a proper way for a great variety 
of imaginary cuts. After putting on the plaster, practise on 
bandaging the parts with strips of cotton cloth rolled for the 
purpose. Practise on using the handkerchief for a variety 
of bandages. 

157. To stop Bleeding from the Arteries. — Locate the 
principal arteries on your own person and that of a friend. 
Let red-crayon marks stand for the course of the arteries. 
Study this part of your anatomy thoroughly. 

Now with strings, cords, shoestrings, handkerchiefs, elastics, 
strips of clothing, practise tying them so as to press deeply 
and firmly in the proper place. Let each one in the class 
practise at the same time on the same artery. Criticise and 
improve each other's work. 

158. Poisons a?id their Antidotes. — Small samples of the 
more common and important poisons should be shown. 
Note carefully the appearance of each one. With each 
sample of poison, arrange its most common antidote. Explain 
exactly how it should be given. 

159. Disinfectants. — Exhibit samples of the common dis- 
infectants, and show how they should be used. Most school- 
premises furnish ample opportunities to make a series of 
practical experiments on ventilation and disinfection. 



REVIEW ANALYSIS 

ALCOHOLIC DRINKS, TOBACCO, AND 
OTHER NARCOTICS 



[The figures in full-face type, in the parentheses, refer to the numbers of the section 
in the preceding chapters of this book.] 



/. The Bones. 

(Chap. ii. p. 13.) 

2. The Muscles. 

(Chap. hi. p. 42.) 



3. Physical 
cise. 



Exer- 



(Chap. iv. p. 56.) 

Food and Drink. 

(Chap. v. p. 70.) 



5. Origin and Na- 
ture of Fer- 
mented Drinks. 



(Chap. 



6. Digestion. 

(Chap. vii. p. 92.) 



Effect of Alcohol and Tobacco on the Bones 
(55). 

1. Effect of Alcohol on the Muscles (44). 

2. Effect of Alcohol on Strength (45). 

3. Effect of Tobacco on the Muscles (46). 

Effect of Alcohol and Tobacco on Physical 
Exercise (58). 

Effect of Drinking Tea and Coffee (72). 

1. Change produced by Fermentation (74). 

2. Ferments and what They do (75). 

3. Alcohol a Poison (76). 

4. Narcotic Poisons (76). 

5. The Alcoholic Appetite (77). 

6. The Evils of Cider-drinking (78). 

7. Wine, and why it should be avoided (79). 

8. Beer: 

Its Origin. 

Relation to Drunkenness (80). 

9. Distilled Liquors (81). 

10. The Cost of the Alcohol Vice. (Note, p. 89. ) 
1 

1. Effect of Alcohol on the Stomach Diges- 

tion (99). 

2. Effect of Alcohol on the Liver (100). 

3. Effect of Tobacco on Digestion (101). 

3 2 9 



330 



REVIEW ANALYSIS 



10. The Nervous 
System. 

(Chap. xi. p. 177.) 



7. The Blood and 
its Circulation. J 

(Chap. viii. p. 122.) 



8. Breathing. 

(Chap. ix. p. 142.) 

9. How the Body is f 

covered. I 

(Chap. x. p. 161.) [_ 



//, The Special f 

Senses. -j 

(Chap. xii. p. 210.) I 

12. Excretion. ( 

(Chap. xiii. p. 235.) ( 

13. Throat and f 

Voice. \ 

(Chap. xiv. p. 243.) I 

14. Simple Matters f 

of Every-day I 
Health. 

(Chap. xv. p. 249.) 



1. How Alcohol gets into the Blood (117). 

2. Effect of Alcohol on the Circulation (116). 

3. Effect of Alcohol upon the Heart (119). 

4. Effect of Tobacco on the Heart ( 120). 

1. Effects of Alcohol and Tobacco upon the 

Lungs ( 132). 

2. Alcohol and the Bodily Heat ( 133). 

3. Alcohol in Hardship. (Note, p. 160). 

1. Effect of Alcohol and Tobacco upon the 
Skin(/45). 

1. Narcotics (162). 

2. General Effect of Alcohol on the Nervous 

System ( 163). 

3. Effect of Alcohol on the Brain Tissue ( 164). 

4. Final Result of Alcoholic Poisoning (165). 

5. Inherited Craving for Alcohol (166). 

6. Tobacco and its Use (167). 

7. Evil Effect of Tobacco. (Note, p. 203.) 

8. Effect of Tobacco upon Young People ( 168). 

9. Tobacco from a Moral Point of View ( 169). 

10. Opium (170). 

11. Practical Points about Opium (171). 

12. Chloral and other Poisons (172). 

Effect of Alcohol and Tobacco on the 
Special Senses ( 196). 

Effect of Alcohol on the Kidneys (202). 

Effect of Alcohol and Tobacco on the Throat 
and Voice (207). 



Pernicious Use of Alcoholic Liquors in 
Accidents and Emergencies (225). 



TEST QUESTIONS FOR REVIEW 



INTRODUCTORY 

[Chapter I. Page i.] 

i. How may the child get some idea that his body 
moves, and is warm ? 

2. What marked difference is there between all 

animals and all vegetables? 

3. How would you compare the body to a locomo- 

tive ? 

4. Can you tell where the comparison fails ? 

5. Explain, in a general way, how we are able to 

cross a room, pick a flower, and do many 
similar acts. 

6. What does the child experience when he touches 

a hot stove, or pricks his finger ? What good 
does pain do ? 

7. Why do we wonder at the marvellous actions of 

our bodies ? 

8. What is meant by anatomy ? physiology ? hy- 

giene ? Illustrate. 

9. What is an organ ? a system ? an apparatus ? 

10. What is meant by the function of an organ ? 

Illustrate. 

1 1. What is a vital organ ? 

12. What is a tissue ? 

331 



332 YOUNG FOLKS PHYSIOLOGY 

13. Mention the principal tissues of the body. 

14. Of what is the minute structure of the body 

made up ? 

15. Tell what you know about cells. 

16. What chemical elements are found in the body ? 

1 7. What can you say about the general build of the 

body ? 

18. Mention the general topics which will be dis- 

cussed in this book. 



THE BONY FRAMEWORK 

[Chapter II. Page 13.] 

1. What do you mean by the skeleton ? What are 

its uses ? 

2. How many bones are there in the human body ? 

3. Describe the composition of bone. 

4. What experiments show the composition of 

bone ? 

5. Explain the general structure of bone. Illustrate. 

6. Explain and give examples of the different kinds 

of bones. 

7. Describe the minute structure of bone. 

8. What is the periosteum ? and what is its use ? 

9. What can you say of the power of bone to resist 

decay ? 

10. Name the principal divisions of the human skel- 

eton. 

11. Into what parts is the head divided? 



TEST QUESTIONS FOR REVIEW 333 

12. What is the cranium ? Mention each bone by 

name. 

13. Give an account of the bones of the cranium. 

14. What is the face ? Name each bone. 

15. Describe the bones of the face. 

16. How are the bones of the head joined together? 

1 7. What are sutures ? Explain fully their use. 

18. What are the fontanelles ? 

19. What is the trunk ? its two cavities? 

20. What is the abdomen ? and what does it contain ? 

21. Describe the diaphragm. 

22. Of what parts does the trunk consist ? Mention 

each bone. 

23. Describe in full the spine. Its uses. 

24. What are the ribs ? what are their uses ? 

25. How are the skull and the spine joined together ? 

26. How are the hips made up ? 

27. Describe the hyoid bone. 

28. Describe the upper limbs. Mention the bones 

of each part. 

29. Describe the three bones of the upper arm. 

30. Describe the two bones of the fore-arm. 

31. Describe the wrist, the palm, and the fingers. 

32. Describe the lower limbs. Name each bone in 

the three parts. 

33. Describe the thigh, the lower leg, the foot. 

34. What is the knee-cap ? the tendon of Achilles ? 

35. Give some points of comparison between the 

hand and the foot. 

36. Explain the use of bones. 

37. How do bones grow ? How are they repaired ? 



334 YOUNG FOLKS PHYSIOLOGY 

38. What is a joint? Describe in full. 

39. Mention the different kinds of joints. Illustrate. 

40. What are the ligaments ? Describe them. What 

are their uses ? Name some important liga- 
ments. 

41. Give some hints about the health of bones. 

42. What is the effect of alcohol upon the bones ? 

43. How does tobacco injure the bones? 

44. Give from memory the " review analysis " of the 

skeleton. 



THE MUSCLES 

[Chapter III. Page 42.] 

1. How do we move ? Explain in full. 

2. What is muscle ? Describe its structure. 

3. Explain and illustrate contraction. 

4. Describe the two general kinds of muscles. 

5. How are muscles arranged to do their work ? 

Illustrate. 

6. What are tendons ? Where are they found ? 

What are their uses ? 

7. Explain how muscles act as levers of the three 

different classes. 

8. Give examples of each class. 

9. What is the number of muscles ? 

10. How are they adapted to different uses ? 

1 1. Mention and describe some of the important mus- 

cles of the body. 

12. How does alcohol affect the control of the mus- 

cles ? 



TEST QUESTIONS FOR REVIEW 335 

13. How does alcohol affect the speech? 

14. Why does alcohol sometimes give rise to the idea 

that it adds to or renews strength ? 

15. How can this idea be shown to be false ? 

16. Explain what is known as fatty decay. 

17. What is the effect of fatty decay on the heart, 

liver, and other organs ? 

18. How do the muscles of the beer-drinker differ 

from those of the total abstainer ? 

19. How does tobacco affect the muscles ? How is 

the effect shown ? 



PHYSICAL EXERCISE 

[Chapter IV. Page 56.] 

1. What is meant by physical exercise ? 

2. Why do we need it ? 

3. What are some of the ill effects of too little exer- 

cise ? 

4. In a general way, describe the effect of exercise 

on the various organs. 

5. How much exercise should we take ? 

6. Mention some points of contrast between health 

and strength. 

7. What is the best time for exercise ? 

8. Give in detail the different kinds of exercise. 

9. Show the beneficial effect of physical exercises 

in schools. 
10. Why is a certain amount of physical training an 
important matter in our school system ? 



336 YOUNG folks' physiology 

ii. Give some points about the importance of physi- 
cal development. 

12. In a general way, tell what you can about the 

various systems of gymnastics. 

13. Give in some detail the essential features of the 

Swedish system. 

14. What are the important features of the German 

system ? 

15. What benefits may be derived from a modern 

gymnasium ? 

16. What system of gymnastics is needed for the 

schools in this country ? 

17. What features are essential for any system to be 

popular and beneficial in our schools ? 



FOOD AND DRINK 

[Chapter V. Page 70.] 

1. To illustrate work, waste, and repair, how may 

you compare the human body to a steam-en- 
gine ? Explain in detail. 

2. How does the comparison fail in some things ? 

3. Why do we need food ? 

4. What are the three great classes of foods ? 

5. Describe and illustrate the nitrogenous foods 

(albumens). Give examples. 

6. What are the starches and sugars ? Give ex- 

amples. 

7. Describe and illustrate the oils and fats. 

8. What is meant by the inorganic or mineral foods ? 



TEST QUESTIONS FOR REVIEW 337 

9. What do you mean by " appetizers " ? Illustrate. 
10. Describe the principal kinds of vegetable food. 
n. Explain the importance of salt, and give many 
illustrations of its value. 

12. What are some of the principal articles of animal 

food ? 

13. What is the use of mineral food ? 

14. What is the natural drink provided by Nature for 

all living things ? 

15. Explain how water acts to rid the body of waste 

and refuse matters. 

16. What is essential for water to be suitable as an 

article of diet ? 

17. Mention some of the more common artificial 

drinks. 

18. Tell what you can about tea, coffee, and cocoa. 

19. What can you say of ice-water ? 

20. In a general way explain the harmful effects of 

tea and coffee. 



ORIGIN AND NATURE OF FERMENTED DRINKS 

[Chapter VI. Page 8i.] 

1. Of what are fruit juices composed ? 

2. How long will such juices remain healthful after 

they have been drawn off from the fruit and 
left standing in ordinary air ? 

3. Why does plant and animal matter decay ? 

4. What name is given to the process of decay that 

goes on in fruit juices that are pressed out 
and left exposed to the air ? 



338 YOUNG folks' physiology 

5. What does fermentation in its widest sense 

include ? 

6. What is the law of fermentation ? 

7. What causes the various processes of decompo- 

sition ? 

8. What would be the condition of the earth if it 

were not for these minute living forms? 

9. To what class or plant family do the disease 

germs belong? 
10. Name other plant cells belonging to this family, 

and tell what they do. 
n. What is the work of the moulds? To what class 

do they belong ? 

12. To what class do the ferments belong ? What is 

their work ? 

13. When do the ferments enter the fruit juice ? 

14. Show what the ferments do in the fruit juice. 

15. What is the nature of the fruit juice before fer- 

mentation ? What is its nature after fermen- 
tation ? Of what law is this an illustation ? 

16. What further changes take place in wine or 

cider when left standing in warm air ? 

17. What would become of the vinegar if left to 

itself ? 

18. What is a poison ? Show why alcohol is a poison. 

19. What are narcotic poisons ? 

20. What are the characteristics of a natural appetite ? 

21. What is the difference between a natural appe- 

tite and the appetite for alcohol ? 

22. Upon what does the character of a substance 

depend ? 



TEST QUESTIONS FOR REVIEW 339 

23. What is the secret of the drunkard's craving for 

alcohol ? 

24. What is the only safeguard against forming the 

alcoholic appetite and the only cure when it is 
formed ? 

25. Why should alcoholic liquors never be used as a 

flavoring for food ? 

26. What is cider ? What poison does it con- 

tain ? 

27. How soon after cider comes from the press can 

alcohol usually be found in it ? 

28. Why is cider an unsafe drink ? 

29. What follows if a person drinks the same quan- 

tity of cider every day while it is growing 
hard ? 

30. From what is wine made ? 

31. Why are we in no danger of being injured by 

alcohol if we take our fruit juices fresh from 
the fruit ? 

32. Why are some wines called " light wines " ? 

Why are these unsafe drinks ? 

33. What disproves the theory that "light wines" 

will prevent the use of stronger drinks ? 

34. From what is beer made ? 

35. Show how alcohol is formed in beer. 

36. What effect does beer appear to have upon the 

moral nature ? 

37. Describe the beer-drinker's appearance and dan- 

gers. 

38. What is the testimony of life-insurance compa- 

nies in regard to beer-drinking ? 



340 YOUNG FOLKS' PHYSIOLOGY 

39. What other drinks are sometimes made by allow- 

ing yeast to act on the sugar of a sweet liquid ? 
Why should no such liquors be made and used 
as beverages ? 

40. Show how distilled liquors are obtained. 

41. How is the craving for the stronger or distilled 

liquors acquired ? 



DIGESTION 

[Chapter VII. Page 92.] 

1. Describe the digestive tube as a whole. 

2. What is meant by digestion ? Name the various 

steps. 

3. What is meant by chewing ? 

4. Describe the structure of a tooth. Mention the 

number and situation of the teeth, giving the 
names of each kind. 

5. What can you tell of the salivary glands and the 

saliva ? Explain what is meant by secretion 
and excretion. 

6. Explain in some detail how we swallow food. 

7. What prevents food from getting up into the 

nose, and down into the windpipe ? Explain 
in full. 

8. Describe the stomach. 

9. What is the gastric juice? How is it secreted ? 

Describe its action. 
10. What are the intestines ? 



TEST QUESTIONS FOR REVIEW 34I 

11. Describe the liver. The bile. The pancreatic 

juice. The intestinal juice. The action of 
each. 

12. In a general way, describe the process of absorp- 

tion. 

13. Describe the process of absorption by means of 

the lacteals and the lymphatics. 

14. What is the thoracic duct and its office ? 

15. Lymphatic glands and the work they do ? 

16. Explain absorption by the blood-vessels. 

17. Describe the .spleen, the thymus and thyroid 

glands. 

18. Describe the large intestines. • 

19. How much should we eat ? Various circumstances 

affecting this question. 

20. What guides have we as to what we should eat ? 

21. Describe in full when we should eat. 

22. How should we eat ? Explain in detail. 

23. Give some practical points about the care of the 

bowels. 

24. Why is a knowledge of proper cooking so neces- 

sary ? 

25. Care of the teeth. Its great importance. Give 

details. 

26. Describe the indigestion due to alcohol. 

27. What is the effect of alcohol on the stomach ? 

28. What is its action on the liver ? 

29. What is the effect of tobacco on digestion ? 



342 YOUNG FOLKS' PHYSIOLOGY 



THE BLOOD AND ITS CIRCULATION 

[Chapter VIII. Page 122.] 

1. Of what use is the blood ? 

2. How is the blood made up ? 

3. What is the total quantity in the body ? 

4. How does it look ? its color ? 

5. How does blood look under the microscope ? 

6. Describe the red blood corpuscles. 

7. Describe the white blood corpuscles. 

8. What is meant by the coagulation of blood ? 

9. How maf you compare the flow of blood circu- 

lation to a force-pump? to the water-system 
of a great city ? 

10. Describe the heart. 

11. Explain the terms auricle, ventricle, valve. 

12. What can you tell of the work done by the 

heart ? 

13. Describe the action of the valves of the heart. 

14. Name the blood-vessels connected with the 

heart. Tell with which part of the heart each 
is connected. 

15. Describe in a general way the differences be- 

tween the veins and arteries. 

16. Describe the aorta. Some of its great branches 

17. What are the veins ? Describe their valves. 

18. To what may the venous system be compared ? 

19. What are the capillaries ? their use ? 

20. Give a general description of the circulation of 

the blood through the body. 



TEST QUESTIONS FOR REVIEW 343 

21. How much time does it take ? 

22. Describe the sounds of the heart. 

23. What is meant by palpitation of the heart ? 

24. What is the pulse ? What may it tell us ? 

25. What is the general effect of alcohol on the 

circulation ? 

26. How does alcohol get into the blood ? 

27. How may alcohol affect the corpuscles of the 

blood ? 

28. In what other way may the blood be injured by 

alcohol ? 

29. What is the effect of alcohol upon the heart ? 

30. What is the harm in thus increasing the fre- 

quency of the heart's beats ? 

31. What is the real cause of the so-called "stimu- 

lating " effect of alcohol on the heart ? 

32. What is the effect of tobacco on the heart ? 



BREATHING 

[Chapter IX. Page 142.] 

1. What is the object of breathing ? 

2. Why do we breathe ? 

3. Describe the air-passages. 

4. How are they lined and protected ? 

5. Give a short description of the lungs. 

6. What is the pleura ? 

7. Describe the mechanical movements of breath- 

ing. 

8. How do we breathe ? 



344 YOUNG FOLKS PHYSIOLOGY 

9. Describe the changes in the air from breathing. 

10. How may we compare the lungs to a market- 

place ? 

11. What is carbonic acid? where found? its poison- 

ous effects ? 

12. What impurities may exist in the air ? 

13. What are the chief dangers from impure air? 

14. What are the practical effects of impure air ? 

15. Why and how should we ventilate ? Give some 

practical plans. 

16. The ventilation of schoolrooms, — why and how 

is it done ? 

17. What is the proper temperature of our living- 

rooms ? Explain in some detail. 

18. Animal heat. How is the body kept warm ? 

19. Explain and illustrate this slow combustion, or 

oxidation. 

20. What is the effect of alcohol upon the lungs ? 

21. Explain in detail the action of alcohol upon the 

bodily heat. 

22. Show how alcohol lessens the power to endure 

hardship and extremes of heat or cold. Give 
illustrations. 



HOW OUR BODIES ARE COVERED 

[Chapter X. Page 161.] 

1. What is the skin ?" and what is its use? 

2. Describe its structure in a general way. 

3. Give in detail a description of the cuticle, or 

scarf-skin. 



TEST QUESTIONS FOR REVIEW 345 

4. Where is the coloring-matter of the skin situ- 

ated ? 

5. Describe the cutis, or true skin. 

6. Show how the skin may absorb poison. 

7. Describe the hair; its structure ; muscles ; num- 

ber of hairs. 

8. Describe the nails. 

9. What care would you take of them ? 

10. What are the oil-glands ? 

11. Describe the sweat-glands. 

12. What is the use of the sweat ? 

13. Give some reasons why we should take care of 

the skin. 

14. Baths. Why, when, and how to take them. 

15. Why do we need clothing ? 

16. Give some hints about the use of clothing. 

17. What is the effect of alcohol upon the skin ? 



THE NERVOUS SYSTEM 

[Chapter XL Page 177.] 

1. Show how the various parts of the body act in 

harmony. 

2. Draw a parallel between the nervous system and 

the telegraph. 

3. Give familiar illustrations to show the general 

action of the nervous system. 

4. What are the two distinct systems ? 

5. What is nerve-tissue? 



346 YOUNG folks' physiology 

6. What are the nerves ? 

7. Give a short description of the brain. 

8. What is the usual size of a human brain ? 

9. Describe fully the cerebrum, or brain proper. 

10. What are the functions of the cerebrum ? 

11. Describe the three coverings of the brain. 

12. Locate and describe the cerebellum. What is its 

function ? 

13. Describe the medulla oblongata. What are its 

functions ? 

14. What do you understand by the cranial nerves ? 

15. How are they arranged? What is the pneumo- 

gastric nerve ? 

16. Describe briefly the spinal cord. What are its 

functions ? 

17. Explain fully what you understand by reflex 

action. 

18. Give several familiar examples to illustrate 

reflex action. 

19. Describe the importance of reflex action. 

20. What are the spinal nerves ? Explain motor and 

sensory nerves. 

21. Describe the sympathetic system of nerves. 

22. What are the functions of the sympathetic 

nerves ? 

23. What tends to keep the nervous system in good 

order ? 

24. What about the abuse of the nervous sys- 

tem ? 

25. Why is sleep necessary? 

26. Give some practical hints about sleep. 



TEST QUESTIONS FOR REVIEW 347 

27. What is one of the most fruitful sources of injury 

to the nervous system ? 

28. What are narcotics ? 

29. Why is the person who takes alcoholic drinks once 

liable to take them again ? 

30. How does alcohol affect the substance of the 

nerves ? 

31. What causes the face to flush when a small quan- 

tity of alcohol has been taken ? 

32. What is the first effect of alcohol on the brain ? 

33. What shows that this unusual activity of the brain 

is an unhealthful excitement ? 

34. What are some of the common liquors that have 

this power to weaken the judgment and blunt 
the mortal sense ? 

35. What part of the brain is first brought under the 

poisonous influence of alcohol ? 

36. How is this shown ? 

37. What part of the brain is next affected when 

larger quantities of alcohol are taken ? 

38. In what way is this shown ? 

39. Describe the last stage of alcohol poisoning. 

40. What injurious effects follow the continual use 

of alcohol ? 

41. What terrible disease often results? 

42. What is the relation of drink to insanity ? 

43. What are some of the other evil consequences 

brought upon the nerves and nervous system 
by the use of alcohol ? 

44. What evil inheritance may result from alcoholic 

habits ? 



348 YOUNG folks' physiology 

45. What are some of the ill effects of tobacco upon 

the nerves ? 

46. How does it affect the mind ? 

47. Show why cigarettes are especially injurious. 

48. How is the effect of tobacco on the moral nature 

frequently shown ? 

49. Why is it no act of kindness to offer a person a 

cigar or cigarette ? 

50. Opium. What is it ? for what used ? what about 

the opium habit ? 

51. Give some practical hints about opium. 

52. What about chloral? other narcotics? 

53. What new drugs are hurtful to health? 



THE SPECIAL SENSES 

[Chapter XII. Page 210.] 

1. What is meant by the term sensation ? Illustrate. 

2. What is the real centre of sensation ? Illustrate. 

3. What are the three organisms necessary to 

receive sensation ? 

4. Give several examples to show this. 

5. Name and define the five special senses. 

6. What is meant by the "muscular sense" ? 

7. Tell how the skin acts as an organ of touch. 

8. What parts of the body are most sensitive to 

touch ? 

9. Does the sense of touch become more sensitive 

by practice ? 



TEST QUESTIONS FOR REVIEW 349 

10. Describe the tongue as the principal organ of 

taste. 

11. Where is the sense of smell located? 

12. How are we able to detect an odor? 

13. What are the uses of the sense of smell ? 

14. What is the sense of hearing ? 

15. Explain in a general way how sound travels 

through the air. 

16. Describe the outer ear. 

1 7. What is the middle ear ? the inner ear ? 

18. Explain just how we are able to hear. 

19. Give some practical hints about the care of the 

ear. 

20. What is meant by the sense of sight ? 

2 1 . What is the eye ? where located ? 

22. Describe the coats of the eye. 

23. Explain in some detail the inner parts of the eye. 

24. Describe in full the mechanism of vision. 

25. What is meant by the term " focus " ? Illustrate. 

26. How are images brought to a focus on the retina ? 

27. Show how the eye is moved by muscles. 

28. What use are the eyelids ? eyebrows ? 

29. Tell what you know of the tears, tear-glands, and 

ducts. 

30. What is meant by color-blindness ? 

31. What is meant by near-sight and far-sight ? 

32. Give some practical hints about the care of the 

eyes. 

33. What is the general effect of alcohol and tobacco 

on the special senses. 

34. How do alcohol and tobacco affect the hearing ? 



350 YOUNG FOLKS PHYSIOLOGY 

35. What effect do they have on the eyes and eye- 

sight ? 

36. Show how cigarettes are especially hurtful to the 

throat and the eyes. 



EXCRETION 

[Chapter XIII. Page 235.] 

1. Why is it necessary to get rid of the waste mat- 

ters of the body ? 

2. How would you compare the body to an engine 

in this matter of getting rid of waste material ? 

3. Describe the principal waste matters of the body. 

4. What are the three great organs of excretion ? 

5. How are their functions related one to the other ? 

6. Describe the kidneys. 

7. What are their functions ? 

8. What is the general effect of alcohol upon the 

kidneys ? 

9. What effect does alcohol have on the tissue-waste ? 

10. How does alcoholic liquor change the structure 

of the kidneys ? 

11. What disease of the kidneys is apt to be induced 

by alcoholic indulgence ? 



THE THROAT AND VOICE 

[Chapter XIV. Page 243.] 

1. What is the throat ? 

2. How is it exposed to disease ? 

3. In what way can you get an idea of the throat ? 



TEST QUESTIONS FOR REVIEW 35 1 

4. What parts of the throat can you see by looking 

into a friend's mouth ? Explain in full. 

5. Describe the pharynx. 

6. Give some hints about the care of the throat. 

7. Describe the organ of speech. 

8. What are the vocal cords ? Describe them. 

9. What is meant by the voice ? 

10. Upon what does the compass of the voice de- 

pend ? 

11. What regulates the quality of the voice? 

12. What is the general effect of alcohol on the voice? 

on the vocal cords ? on the delicate lining of 
the throat ? 

13. How does tobacco affect the vocal cords ? 

14. How is sore throat frequently caused ? 

15. How do cigarettes affect the throat-passages and 

the voice ? 



SIMPLE MATTERS OF EVERY-DAY HEALTH 

[Chapter XV. Page 249.] 

1. What is meant by "simple matters of every-day 

health " ? 

2. Mention some things of the kind likely to happen. 

3. What real good may one do under such cir- 

cumstances ? 

4. Describe in detail the process of making poul- 

tices. 

5. When and how would you use them ? 

6. What would you do for a fainting person ? 



352 YOUNG FOLKS' PHYSIOLOGY 

7. Convulsions, and what to do for them. 

8. What is meant by asphyxia? What is the treat 

ment ? 

9. Describe in detail what is to be done in apparent 

drowning. 

10. What is sunstroke or heatstroke? What would 

you do ? 

1 1. How would you know that a bone was broken ? 

12. How would you manage with a broken bone ? 

13. How would you carry an injured person ? 

14. What is the treatment for burns and scalds ? 

15. What is frost-bite ? What would you do for it ? 

16. What would you do for a foreign body in the 

throat ? in the nose ? in the ear ? in the eye ? 

17. How would you know the difference between 

bleeding from an artery and bleeding from a 
vein ? 

18. On what general principles would you act to stop 

bleeding ? 

19. What would you do to stop bleeding from an 

artery ? from a vein ? 

20. Can you tell the difference between blood com- 

ing from the lungs and that from the stomach ? 
If so, how ? 

21. What would you do for nose-bleed ? bruises ? cut 

and torn wounds ? 

22. What will you say about the pernicious use of 

alcoholic liquors in accidents and emergen- 
cies ? 

23. Describe in detail how you would make a sick- 

room look neat and clean. 



TEST QUESTIONS FOR REVIEW 353 

24. How would you make a sick person more com- 

fortable ? 

25. Are persons likely to swallow poisons acciden- 

tally ? If so, when ? Mention some poisons 
often accidentally swallowed. 

26. What general treatment would you give for all 

poisons ? 

27. Describe the more common acid poisons, and 

give their antidotes. 

28. Mention the alkaline poisons. Their antidotes. 

29. Mention some metallic poisons, and give an- 

tidotes. 

30. Mention some narcotic poisons. Their antidotes. 

31. What other things may act as poisons ? 

32. How may the air be poisoned ? 

33. What is meant by disinfection ? 

34. In what general way would you use disinfectants ? 

35. Mention the three most common disinfectants. 

36. Describe in detail how disinfectants should be 

used. 



NOTES 



ADDITIONAL TESTIMONY CONCERNING THE NATURE AND 
EFFECTS OF ALCOHOLIC DRINKS AND OTHER NARCOTICS. 

Note i. — " Besides the danger connected with the use of 
alcoholic drinks, which is common to them with other nar- 
cotic poisons, alcohol retards the growth of young cells and 
prevents their proper development. Now, the bodies of all 
animals are made up largely of cells, as heretofore shown, 
and the cells being the living part of the animal, it is espe- 
cially important that they should not be injured or badly 
nourished while they are growing. So that alcohol in all its 
forms is particularly injurious to young persons, as it retards 
their growth and stunts both body and mind. This is the 
theory of Dr. Lionel S. Beale, a celebrated microscopist and 
thinker, and is quite generally accepted." — Dr. Roger S. 
Tracy. 

" On entering college (Yale), the class of '91 had a list of 
thirty-eight tobacco-users, or about eighteen per cent of the 
two hundred and five men. At the beginning of junior year 
this percentage had been slightly increased, although eigh- 
teen of the men who had been recorded as tobacco-users 
had left college for one reason or another. At the end of 
senior year the record stands as follows : — 

" There are seventy-seven men who never used tobacco. 

" There are twenty-two men who have used it slightly at 
rare intervals, of whom six have begun the practice in the 
last term of senior year. 

355 



356 YOUNG folks' physiology 

There are eighteen who have beeD hard smokers at differ- 
ent periods of the course. 

•• There are seventy men who have used it regularly. . . . 

,; In weight the non-users increased io.4 r c more than the 
regular users, and 6.6fc more than the occasional users. In 
the growth of height the non-users increased twenty-four per 
cent more than the regular users, and fourteen per cent more 
than the occasional users." — Prof. J. TV. Seaver, 31.D., of 
Yale, in the University Magazine, June. 1S91. 

•* Smoking prevents a healthy nutrition of the several 
structures of the body. Hence comes, especially in young 
persons, an arrest of the growth of the body, low stature, an 
unhealthy supply of blood, and weak bodily powers." — Dr. 
f. Copland, F.R.S.. of England. 

" When the Europeans first visited Xew Zealand, they 
found the natives the most finely developed and powerful 
men among the islands of the Pacific. Since the introduc- 
tion of tobacco, for which these men developed a passionate 
liking, they have, from this cause alone, become decimated 
in numbers, and so reduced in stature and physical well- 
being as to be an altogether inferior type of men." — A>K' 
York Medical Journal. 

Note 2. — •• Dr. Parkes made three soldiers march twenty 
miles a day for six days, loaded with gun, knapsack, pouch, 
etc. They had the same food even- day ; but on two days 
they drank brandy and water, on two coffee, and on the 
other two weak beef-tea. All three found that, though the 
spirit revived them for a little while, they were more tired 
at the end of the journey on the two days when they took 
brandy than on any of the other two." — Dr. A 5. Davis. 

" There is no muscle about beer. This is abundantly 
illustrated bv the thousands of beer and wine drinkers, who. 



notes 357 

« 

from twenty to twenty-five years of age, were muscular, 
active, capable of any reasonable endurance, with a weight 
of one hundred and fifty pounds, but who, after moderately 
retarding atomic changes, and retaining old atoms by the 
daily use of wine or beer, have acquired a weight of two 
hundred pounds or more, and have lost their muscular activ- 
ity and endurance to such an extent that active exercise of 
twenty minutes would make them puff like a heavy horse." — 
Dr. N. S. Davis. 

" It has been demonstrated on all sides, at the forge, in the 
workshop, in the field, on the march, in the arctic region, and 
in the torrid zone, in physical and in intellectual labor, that 
the spirit-drinker fails to cope with the temperate man." — 
Dr. Willard Parker. 

" It is now well known and acknowledged by scientific 
men, that less muscular labor can be performed under the 
influence of alcohol, in whatever quantity, than without it. 
In the performance of great feats of strength and endur- 
ance, as in the case of Weston, the famous pedestrian, alcohol 
has been avoided ; and in the harvest-field and the work- 
shop, and with contestants in the ancient Roman games, 
the advantage has ever been with abstainers. The most 
conclusive tests have been in armies in severe marches, 
where accurate observation on a large scale has been- made 
by intelligent medical and commanding officers. In all such 
tests, whether in hot or cold climates and seasons, — in 
Africa, India, Russia, and Canada — in our own country and 
everywhere, it has been shown that those soldiers who 
abstained from alcohol could accomplish and endure more 
than those who indulged in it, however moderately or freely. 
In emergencies, those officers who allow its use at all find 
that it must be given when the men have accomplished their 
day's work and are resting after their labor. It may then 



358 YOUNG folks' physiology 

blunt the sense of fatigue and promote sleep, but, unfortu- 
nately, it lessens the power of work for the next day, and if 
its use becomes habitual, other mischief will be done." — 
Dr. A. B. Palmer. 

" Voluntary muscular power seems to be lessened, and this 
is most marked when a large amount of alcohol is taken at 
once ; the finer combined movements are less perfectly made. 
Whether this is by direct action on the muscular fibres, or 
by the influence on the nerves, is not certain. In very large 
doses it paralyzes either the respiratory muscles or the nerves 
supplying them, and death sometimes occurs from the im- 
pairment to respiration." — Dr. Edmund A. Parkes, F.R.S. 

Note 3. — " One of the first things demanded of a young 
man who is going into training for a boat-race is, ' Stop 
smoking.' And he himself, long before his body has reached 
its highest point of purity and development, will become 
conscious of the lowering and disturbing effects of smoking 
one inch of a mild cigar. No smoker who has ever trained 
severely for a race, or a game, or a fight, needs to be told that 
smoking reduces the tone of his system : he knows it." — 
James Parton. 

" A man who, after election as a member of his college 
crew, should be found secretly drinking beer or smoking, 
would be hissed out of college." — Dr. H. Newell Martin. 

Note 4. — (t All that has lived must die, all that is dead 
must be disintegrated, dissolved, or gasified ; the elements 
which are the substratum of life must enter into new cycles 
of life. If things were otherwise the matter of organized 
beings would encumber the earth, and the law of the perpe- 
tuity of life would be compromised by the gradual exhaustion 
of its materials. One grand phenomenon presides over 
this vast work — the phenomenon of fermentation. . . . 



notes 359 

" Fermentation and putrefaction only represent the first 
phase of the return to the atmosphere and to the soil of all 
that has lived. Fermentation and putrefaction give rise to 
substances which are still very complex, although they repre- 
sent the products of decomposition of fermentable matters. 
When sugar ferments a large portion of it becomes gas ; but 
alongside of the carbonic acid gas which is formed, and 
which is, indeed, a partial return of the sugar to the atmos- 
phere, new substances, such as alcohol, succinic acid, glyce- 
rine, and materials of yeast, are produced. When the flesh 
of animals putrefies, certain products of decomposition, also 
very complex, are formed, with the vapor of water and other 
gases of putrefaction." — "Louis Pasteur: His Life and 
Labors." 

Note 5. — "It has been known since very ancient times 
that sweet juices of fruits, more particularly of the grape, 
can be made to undergo certain changes, the result of which 
is that the juice is no longer a sweet, innocuous liquid, but 
possesses intoxicating properties. During the occurrence of 
this change the clear fluid becomes turbid, and its surface is 
covered by bubbles or froth. This latter phenomenon 
attracting special attention, the name fermentation was given 
to the process. We now know that the change consists in 
the transformation of the sweet substance sugar into other 
materials, of which the most abundant are alcohol, the body 
possessing the intoxicating properties, and carbonic acid, the 
evolution of which causes the frothing. The turbidity of 
the liquid is caused by the presence of numerous unicellular 
organisms, which increase rapidly by a process of budding." 
— Halliburton's " Text Book of Chemical Physiology and 
Pathology." 

" Thus in the destruction of that which has lived, all 



360 YOUNG FOLKS* PHYSIOLOGY 

reduces itself to the simultaneous action of these three great 
phenomena, — putrefaction, fermentation, and slow combus- 
tion. A living organism dies, animal, plant, or mineral, or 
the remains of the one or the other. It is exposed to the 
contact of the air. To the life which has quitted it, succeeds 
life under other forms. In the superficial part which the air 
can reach, the germs of the infinitely small aerobies (micro- 
organisms which cannot live without free oxygen) hatch and 
multiply themselves. The carbon, the hydrogen, and the 
nitrogen of the organic matters are transformed by the oxy- 
gen of the air, and under the influence of the life of these 
aerobies, into carbonic acid, vapor of water, and ammonia 
gas. As long as organic matter and air are present, these 
combustions will continue. While these superficial combus- 
tions are going on, fermentation and putrefaction are doing 
their work in the interior of the mass by the developed 
germs of the anaerobies, which not only do not require 
oxygen for their life, but which oxygen actually kills. 
Little by little, at length, by this work of fermentation and 
slow combustion, the phenomenon is accomplished. Wheth- 
er in the free atmosphere or under the earth, which is always 
more or less impregnated with air, all animal and vegetable 
matters end by disappearing. To arrest these phenomena, 
an extremely low temperature is required. It is thus that in 
the ice of the Polar region antediluvian elephants have been 
found perfectly intact. The microscopic organisms could 
not live in so cold a temperature. These facts still further 
strengthen all the new ideas as to the important part per- 
formed by these infinitely small organisms, which are, in 
fact, the masters of the world. If we could suppress their 
work, which is always going on, the surface of the globe, 
encumbered with organic matter, would soon become unin- 
habitable." — " Louis Pasteur : His Life and Labors" 



NOTES 36l 

Note 6. — " It is entirely safe to say that there is not an 
occupation or condition in human society in which those who 
use any variety of fermented or distilled liquors, even in the 
most ' decent and orderly manner,' do not furnish more cases 
of sickness and more deaths annually than are furnished by 
an equal number occupying the same conditions but totally 
abstaining from all drinks." — Dr. N. S. Davis. 

"Alcohol taken into the body paralyzes and weakens the 
nerves, hardens and contracts the animal fibre ; the capillaries, 
arteries, veins, lymphatics, or other canals and ducts for 
conveying fluids, are lessened in their diameter, and are 
ultimately obstructed, so that the foundation is laid for many 
diseases." — Dr. John Higginbottom, F.R.S. 

Dr. Henry Thompson, an English physician of large 
practice, declares that he has " no hesitation in attributing a 
very large proportion of the most painful and dangerous 
maladies to the ordinary and daily use of fermented drinks 
in quantities conventionally deemed moderate." 

" I state unhesitatingly that from experience and observa- 
tion, the use of light wines and beer is positively injurious 
to many persons ; and I am forced to believe that even if in 
others no pernicious effects be observed immediately, such 
effects will become apparent sooner or later." — Dr. T. F. 
Allen of New York City. 

" I would say that both theoretically and practically, I do 
not believe in even a moderate use of light wines and beer as 
a beverage. The harm they do will not be manifested 
usually during perfect health ; but in times of severe sickness 
I believe a person's power to resist disease is in proportion 
to his abstinence from all forms of liquor, even in the light 
forms." — Dr. B. N. Bridgeman. 

" In addition to the injurious effects morally, which the 
moderate use of alcohol produces, and all drunkenness is 



362 YOUNG FOLKS' FHYSIOLOGY 

born of it, it is injurious physically also I believe, and chiefly 
so in the following ways : (a) alcohol acts detrimentally upon 
the blood corpuscles and fibrinous elements of the blood, pro- 
ducing a ragged or cog-wheel margin of the former, and 
ready coagulation of the latter, with hardening of the coats 
and consequent loss of elasticity of the blood-vessels, thus 
producing the most favorable condition for plugging of the 
capillaries, (b) By its action upon the mucous membrane of 
the alimentary canal and other portions of the body, the 
system is less amenable to remedies and constant repair. 
(c) It increases the tendency to congestion and inflammation 
generally, and in many cases produces a fatal result in a not 
necessarily fatal disease, {d I What is true in health is even 
more true in disease, and I believe that even more cases of 
pneumonia succumb through its use that might otherwise 
recover." — Dr. D. G. Dowkoutt. 

Note 7. — "I can see nothing in the action of alcohol in 
the human body, in any case or at any time, but that of a 
paralyzer : and I see in that view the key by which we can 
explain all the contradictory phenomena and all the contra- 
dictor}- benefits which have been ascribed to the influence of 
alcohol."* — Dr. James Ethan 

'• Alcohol, the rectified product of the vinous fermentation 
(i. e.. decomposition) of various saccharine fluids, and in- 
cluded by chemists among the narcotic poisons, exerc: 
metamorphosic effect on every organ of the human body." — 
Dr. Felix Oswald. 

'• Alcohol, for all intents and purposes, may be regarded 
as a sedative or narcotic rather than a stimulant." — D>: 
Samuel Milks. 

'• The whole class of alcoholic liquors may be considered 
as narcotics, producing very little difference in their ultimate 
effects on the system." — Dr. William B 



NOTES 363 

" The flushing of the face (produced by alcohol) is caused 
by the paralysis of the cervical branch of the sympathetic 
nerve. This symptom usually occurs some time before the 
conspicuous manifestation of the ordinary signs of intoxica- 
tion which result in paralysis of the cerebrum ; we may 
search in vain among the phenomena of intoxication for any 
genuine evidence of that heightened mental activity which is 
said to be followed by depressive recoil. There is no recoil, 
there is no stimulation. There is nothing but paralytic dis- 
order from the moment narcosis begins." — Prof . John JFiske, 
of Cambridge, Mass. 

" It is the diminution of nerve sensibility that renders the 
individual at first light, airy, and hilarious, giving the popu- 
lar idea of excitement or stimulation ; second, dull, hesitat- 
ing, or incoherent in thought or speech, and unsteady or 
swaggering in gait, a stage popularly recognized as incipient 
intoxication ; and third, brings on entire unconsciousness 
and muscular paralysis, constituting dead drunkenness or 
complete anaesthesia. These successive stages are devel- 
oped in direct ratio to the quantity taken." — Dr. JV. S. 
Davis. 

Note 8. — " The habitual use of alcoholic liquids, by the 
anaesthetic effect of alcohol on the human system, tends con- 
stantly to create an appetite for more, and consequently 
moderation from the beginning very generally leads directly 
to excess sooner or later." — Dr. JV. S. Davis. 

" I observed as a physiological or, perhaps, psychological 
fact, that the attraction of alcohol for itself is cumulative : 
that so long as it is present in the human body, even in 
small quantities, the longing for it, the sense of requirement 
for it, is present, and that as the amount of it insidiously 
increases, so does the desire." — Dr. B. W. Richardson. 



364 YOUNG FOLKS' PHYSIOLOGY 

" Alcohol creates an appetite for itself that soon becomes 
irresistible, and every drunkard will admit that when he be- 
gan to drink he had no intention of becoming a drunkard." 

— Dr. R. Gowans. 

" The physician who prescribes narcotics is dogged by the 
ever-present danger that his patients may acquire a craving 
for the drugs thus ordered. ... It is a common experience 
that a morphia or a chloral habit owes its origin to the 
orders of a medical attendant, who has therefore incurred a 
most serious responsibility. Alcohol, as the temperance 
reformers have so long insisted, must be included in the list." 

— The Birmingham Medical Review. 

" In the case of moderate drinking, either of malt or 
spirituous liquors, there is small hope that the habitual 
drinker will remain a moderate one." — A. G. Bullock, Presi- 
dent Mutual Life Insurance Company. 

"The power of moral resistance is weakened with every 
repetition of the poison dose." — Dr. Felix Oswald. 

" It is the temperate use of alcohol that creates the appe- 
tite of the inebriate." — Dr. William Hargreaves. 

" It will be admitted, I presume, by all who hear me that 
if there were no temperate drinking there would be none 
that is intemperate. Men do not begin by what is usually 
called immoderate indulgence, but by that which they regard 
as moderate. Gradually and insensibly their draughts are 
increased until the functions of life are permanently dis- 
turbed, the system becomes inflamed, and there is that 
morbid appetite which will hardly brook restraint, and the 
indulgence of which is sottish intemperance. Let it be 
remembered, then, that what is usually styled temperate 
drinking stands as the condition precedent of that which is 
intemperate. Discontinue one and the other becomes im- 
possible." — From an address by A. Potter, D.D., late Bishop 
of the Diocese of Pennsylvania. 



NOTES 365 

Note 9. — " Of 623 moderate and immoderate drinkers 
with whom I have conversed, 337 tell me that they acquired 
the desire for wine and other alcoholic poisons by their use 
in articles of diet, and in the family and social circles, dealt 
out to them by their wives, and sisters, and female friends. 
Of this number, 161 cases (more than twenty-five per cent) 
were from the use of liquors in articles of diet. Of the 
whole number referred to, 328 fill a drunkard's grave." — A 
physician prominently cofinected with a leading life-insurance 
company. 

Note 10. — " We have been told in America, and I fully 
believed it, that if a people could be supplied with a cheap 
wine, they would not get drunk — that the natural desire for 
some sort of stimulant would be gratified in a way that 
would be not only harmless to morals, but conducive to 
health. I am thoroughly undeceived. The people drink 
their white wine here to drunkenness. ... So this question 
is settled in my mind. Cheap wine is not the cure of in- 
temperance. The people here are just as intemperate as 
they are in America ; and, what is more, there is no public 
sentiment that checks intemperance in the least. The wine 
is fed freely to children, and by all classes is regarded as a 
perfectly legitimate drink. ... I firmly believe that the 
wines of Switzerland are of no use except to keep out whis- 
key, and the advantages of the wine over the whiskey are not 
very obvious. It is the testimony of the best men in Switzer- 
land — those who have the highest good of the people at 
heart — that the increased growth of the grape has been 
steadily and correspondingly attended by the increase of 
drunkenness. They lament the planting of a new vineyard 
as we at home lament the opening of a new grog-shop. 
They expect no good of it to anybody. They know and 



5-6 YOUNG folks' physiology 

deeply feel that the whole wine-producing enterprise is 
charged with degradation for their country." — Dr. J, G. 
Holland, in the Springfield Republican. 

" That wine will intoxicate, does intoxicate, that there are 
confirmed drunkards in Paris and throughout France, is 
notorious and undeniable. You can hardly open a French 
newspaper that does not contain some account of a robbery 
perpetrated upon some person stupefied by over-drinking, — 
a police case growing out of a quarrel over the wine-cup, or 
a culprit, when asked why the sentence of law should not be 
pronounced on him, replying, 'I was drunk when this hap- 
pened, and know nothing of the matter.' That journeymen 
are commonly less fitted for and less inclined to work on 
Monday than on other days of the week is as notorious here 
as it ever was in any other rum-drinking city." — Horace 
Greeley, in a letter from Paris. 

"In September, 1887, the French Minister of Finance 
organized an alcoholic commission of which M. Leon Say 
was made president, to investigate the subject of alcoholism. 
In his report, which has since been published, he deals with 
the hygienic aspects, and represents that alcoholism is to-day 
in France one of the most serious dangers of the times. Not 
only men, but women and children, are affected. Mental 
diseases hitherto unknown have become common. A pre- 
vious commission, appointed by the French Senate in 1886, 
reported that alcoholism threatened the people of France 
with rapid degeneration." — Dr. K. Mitchell. 

'• I had entertained a hope that the manufacture of pure 
wines and their introduction into general use would crowd out 
the gross strong liquors and diminish intemperance. I am 
now fully convinced that this hope was groundless and 
delusive. In wine-growing districts intemperance is on the 
increase, extending to the youth of both sexes." — Rev. Dr. 
Stone of California, formerly of Park-street Church, Boston. 



NOTES 367 

The editor of the Pacific says, " Wine has become as cheap 
as milk, and is as freely drunk, till many once sober men are 
growing habitually intoxicated. One leading man enumer- 
ated to us five of his acquaintances who, once noble men, are 
now drunkards through wine." 

" A few weeks ago there arrived at my house a niece of 
mine from the missionaries in Persia, born in that vine-grow- 
ing land and familiar with the habits of the people. She 
repeats the testimony given by her father in 1867 at our 
State House, before the License Committee. This young 
lady speaks of the lamentable ravages of intemperance in that 
land at the present time, caused by using the wine made 
from the pure juice of the grape. They have large earthen 
jars, one-third sunk in the ground, and so high that a man 
must stand on a stool to reach the top. These are filled with 
grape-juice ; sheepskin is stretched over the top and plas- 
tered with clay. After some two months it is fermented ; 
but as it will turn to vinegar in a few weeks if opened, a 
man invites his friends, and for a week or ten days, till his jar 
is empty, they continue in a state of beastly intoxication. 
After a time a neighbor opens one of his jars, and a similar 
scene is enacted." — Rev. A. H. Plumb, D.D., in an address 
given in Tremont Temple, March, 188 1. 

Note ii. — "A copious beer-drinker is all one vital part. 
He wears his heart on his sleeve, bare to a death-wound even 
from a rusty nail or the claw of a cat." — Dr. Grinrod, a 
prominent London physician. 

John S. Ford, writing from Milwaukee, Wis., to The Boston 
Traveller, says, " Physicians of this city who have had wide 
experience are of the opinion that the person who uses beer 
habitually is more liable to contract disease and less liable 
to throw it off than one who abstains from its use. A case 



368 YOUNG folks" physiology 

recently occurred of a German brewer, apparently healthv 
anci robust, who accidentally stuck a small sliver in his hand. 
Soon his arm began to swell and be painful, and the pain and 
swelling extended to the entire body, and resulted in death. 
The symptoms were clearly those of a bad condition of the 
blood, and no other explanation could be given than poison- 
ing by the use of lager beer." 

Note 12. — Prof. H. A. Hare, of the University of Penn- 
sylvania, made seventeen experiments, and every one of them 
very clearly showed that the beer retarded both the salivary 
and gastric digestion. 

Prof. Duggan, of Johns Hopkins University, found that 
alcohol in any form retarded the digestion of starch in a 
marked degree. 

Prof. Paul Bert ascertained that even small doses of 
spirits delayed digestion for the first two hours till absorption 
of the liquor had been mostly effected. 

When Dr. Beaumont was experimenting on Alexis St. 
Martin he gave him a glass of gin, when the digestive process 
was at once arrested, and did not be°dn a°;ain until after the 
absorption of the spirit, after which it was slowly renewed 
and tardily finished. 

"It is an entirely false idea that alcohol acts as an aid to 
digestion." — Dr. B. IV. Richardson. 

u It is commonly thought that alcoholic drinks act as aids 
to digestion. In reality, it would appear that the contrary is 
the case. Any one may make the observation on himself 
that a meal without alcohol is more quickly followed by hun- 
ger than when alcohol is taken. The inhibitory influence of 
alcohol on digestion has been observed on a patient with a 
gastric fistula, on several other persons by the aid of the 
stomach pump, and by means of numerous other experi- 



NOTES 369 

ments." — Prof. G. Bunge, of the University of Basle, 
Switzerland. 

" The moderate use of strong drinks is always unhealthy, 
even when the body is in a healthy condition. It does not 
do any good to the digestion, but even interferes with that 
process ; for strong drink can only temporarily increase the 
feeling of hunger, but not in favor of digestion ; after which 
strong reaction must follow, and evils which are usually attrib- 
uted to other causes often result from their habitual use 
with moderate drinkers." — Six hundred physicians of the 
Netherlands. 

Note 13. — " The organ of the body which most frequently 
undergoes structural change from alcohol is the liver. The 
capacity of this organ for holding active substances in its 
cellular parts is one of its marked physiological distinctions. 
In instances of poisoning by arsenic, antimony, strychnine, 
and other poisonous compounds, we find, in conducting our 
analyses, the liver to be, as it were, the central depot of the 
foreign matter. It is practically the same in poisoning with 
alcohol. The liver of the confirmed alcoholic is probably 
never free from the influence of the poison ; it is too often sat- 
urated with it. 

. The effect of the alcohol upon the liver is through the 
minute membranous or capsular structure of the organ upon 
which it acts to prevent the proper dialysis and free secre- 
tion. The organ at first becomes large from the distention 
of its vessels, the surcharge of fluid matter, and the thicken- 
ing of tissue. After a time there follow contraction of mem- 
brane and slow shrinking of the whole mass of the organ 
in its cellular parts, owing to the obstruction offered to the 
returning blood by the veins, and death is certain." — Dr. 
B. W. Richardson. 



37<D YOUNG FOLKS PHYSIOLOGY 

" The first effect of alcohol on the liver is to irritate it, 
just as it irritates the mouth and stomach, or, when applied 
strong enough, the skin. It causes distention of the blood- 
vessels and an accumulation of a larger amount of blood in 
them than there should be. This results in a swelling of the 
organ, partly from the larger quantity of blood in the vessels, 
and partly from effusion into it and an increase of tissue. 
This change in the liver causes a change in its action ; and its 
important work of preparing the food carried to it and 
making it ready for the uses of the body, its office of making 
blood, of changing waste matter so that it can be carried 
out of the system by other organs, and its work of secreting 
bile, are all imperfectly done. 

" This defective work leads to general derangement of the 
whole system. There is what is called biliousness — disturb- 
ance of the stomach, a coated tongue, foul breath, deranged 
bowels, headache, dizziness, dimness of sight, distressing 
dreams, a feeling in the side and stomach, and general uncom- 
fortable sensations. Notwithstanding that these unpleasant 
effects are so frequently produced by what are regarded as 
moderate quantities of wine, beer, or spirits, yet each drink, 
by its narcotic or soothing effect upon the brain and nerves, 
may make the person feel better for the time, just as the 
distress produced by opium-eating is temporarily relieved by 
repeating the dose. 

" But much more serious effects are sometimes produced by 
alcoholics ; and beer is more apt to act in the way about to be 
mentioned than whiskey. An accumulation of fat is often 
produced in the liver, causing its greater and more perma- 
nent enlargement, and impairing more permanently its action. 
When this is the case, stopping the drink does not produce 
the same rapid improvement as in the cases before mentioned. 
But where the fat is deposited between the proper liver cells, 



NOTES 371 

or structures, without taking the place of them, abstaining 
from drink may in time be followed by much improvement. 
There is another fatty change much worse than this where 
particles of fat take the place of the structure. This is 
called fatty degeneration, and where it occurs other organs 
are likely to be affected in a similar way ; and this disease 
before a great while ends in death. When any portion of the 
liver tissue is changed into fat, that part cannot do its work, 
and as that change goes on action will cease and death will 
follow." — Dr. A. B. Palmer, late Dea7i of the Medical Depart- 
ment of the Michiga?i University. 

Note 14. — "It (tobacco) lessens the natural appetite, 
more or less impairs digestion, and induces constipation, 
while it irritates the mouth and throat, rendering it habitually 
congested, and destroying the purity of the voice. It in- 
duces an habitual sense of uneasiness and nervousness, with 
epigastric sinking, or tension, palpitation, hypochondriasis, 
neuralgia." — Prof. Alfred Stille, Professor of Theory and 
Practice of Medicine in the Ufiiversity of Pefinsylvania. 

" Tobacco gives rise to debility of the stomach and nau- 
sea." — Dr. B. W. Richardson. 

Note 15. — " Alcohol even in small quantities acts on the 
nerve pabulum in the blood, preventing its taking up oxygen 
and exhaling carbonic acid." — Dr. George Harley, P.P.S. 

" Alcohol stimulates the blood discs to an increased and 
unnatural contraction, which hurries them to the last stage of 
development — that is, induces their premature decay and 
death. The coloring matter is dissolved out of them and the 
pale discs lose their vitality, whence less oxygen can be 
absorbed." — Prof Shultz. 

11 In the ordinary use of alcoholic drinks enough alcohol is 



3/2 YOUNG FOLKS PHYSIOLOGY 

not taken to produce death by coagulation of the albumen of 
the blood, but this affords no warrant for assuming that the 
lesser quantity is neutral or inactive. . . . Just to the extent 
in which it is present it must exert an unhealthy, abnormal 
influence upon the albumen." — Prof. E. L. You mans. 

" With all parts of the blood, with the water, fibrine, albu- 
men, salts, fatty matter, and corpuscles, the alcohol comes in 
contact when it enters the blood, and. if it be in sufficient 
quantity, it produces disturbing action. I have watched this 
disturbance very carefully on the blood corpuscles; for in 
some animals we can see these floating along during life, 
and we can also observe them from men who are under the 
influence of alcohol by removing a speck of blood and 
examining it with the microscope. The action of alcohol, 
when it is observable, is varied. It may cause the corpuscles 
to run too closely together and to adhere in rolls ; it may 
modify the outline, making the clear-defined, smooth, outer 
edge irregular or crenate. or even star-like : it may change 
the round corpuscles into the oval form, or, in very extreme 
cases, it may produce what I may call a truncated form of 
corpuscles, in which the change is so great that if we did not 
trace it through all its stages, we should be puzzled to know 
whether the object looked at were indeed a blood-cell. All 
these changes are due to the action of the spirit on the water 
contained in the corpuscles. — upon the capacity of the 
spirit to extract water from them. During even- stage of 
modification of corpuscle thus described, their function to 
absorb and fix gases is impaired, and when the aggregation 
of cells in masses is great, other difficulties arise, for the 
cells united together pass less easily than they should through 
the minute vessels of the lungs and of the general circulation 
and impede the current, by which local injur}- is produced." 
— Dr. B. W. Rich 



notes. 373 

Note 16. — " Within the last few years experiments of the 
most exact and conclusive character have been made by 
skilled investigators, to determine the action of alcohol on 
the hearts of animals. . . . Among the most careful and 
skilful experiments on this subject are those of Drs. Sidney 
Ringer and Harrington Gainsbury of London. . . . These 
experiments made upon the hearts of frogs were instituted for 
the purpose of determining the comparative eifects of the 
different alcohols in their direct action upon that organ. 
It was found that all the alcohols (including common 
alcohol, the active principle in all our liquors) diminished 
the force of the heart's action, and arrested it in a longer or 
shorter time, in exact proportion to the strength of the 
respective articles and the quantity applied. A long series 
of experiments furnished the same results and demonstrated 
their correctness. Common alcohol is weaker and lighter 
than some of the other rarer alcohols, but heavier and 
stronger than others ; but the effect in character was the same 
in all, differing only in degree. These eminent experi- 
menters, in closing the report on these articles, declared that, 
' by their direct action upon the cardiac tissue, these drugs 
are clearly paralyzants ' (and not stimulating), and that this 
appears to be the case from the outset, no stage of increased 
force or contraction preceding. 

Prof. Martin, of Johns Hopkins University, who has written 
an excellent work on physiology, and who stands among the 
very highest in this country as an experimental physiologist, 
has made experiments with the view of determining the 
precise effect of common alcohol, when in the blood in cer- 
tain proportions, upon that organ. The results of these 
experiments have not been contradicted by any other experi- 
ments of a similar character, and they conclusively prove 
that the direct action of alcohol on the heart is paralyzing 
and not stimulating. 



374 YOUNG FOLKS PHYSIOLOGY 

" It is true that alcohol often, indeed generally, increases 
the frequency of the heart's action, but not its force, when in 
a previously healthy state ; except perhaps in cases where it 
excites feverishness, which is a diseased condition. Great 
frequency of the pulse is an evidence of weakness rather 
than of strength." — Dr. A. B. Palmer. 

Note 17. — " Tobacco-smoking often causes an intermit- 
tent pulse. Out of eighty-one smokers examined, twenty- 
three presented an intermittent pulse, independent of any 
cardiac lesion. This intermittency disappeared when the 
habit of smoking was abandoned. Among children from 
nine to fifteen years of age, smoking undoubtedly caused 
palpitation, intermittent pulse, and chloro-anaema. 

The irregularity of the heart's action, which tobacco causes, 
is one of its most conspicuous effects. Candidates are annu- 
ally rejected for cardiac disturbances, who have subsequently 
admitted the use of tobacco, and the annual physical exami- 
nation of cadets reveals a large number of irritable hearts 
(tobacco hearts) among boys, who had no such trouble when 
they entered school. Among the applicants for enlistment 
as apprentices in the navy during the year 1879, ten in a 
thousand were rejected for functional lesions of the heart, 
indicating tobacco poisoning." 

Dr. Frangel, of Berlin, says that in his country, " while ever 
immoderate smoking may appear to agree with persons foi 
many years, suddenly, and without any other assignable cause, 
trouble with the heart begins, and a physician is consulted. 
These troubles seldom begin until the smoker has passed 
his thirteenth year, and usually appear at an age between 
fifty and sixty." 



APPENDIX 



LIGHT GYMNASTIC EXERCISES 

Value of Physical Exercises. — In preceding chap- 
ters [Chapters III. and IV.] of this book we have 
discussed the importance of physical exercises, and 
have alluded to the value of light 
gymnastics as cheap and conven- 
ient means of giving muscular 
strength and vigor to all parts of 
the body. 

It was claimed that children 
should be trained every day at 
home or at school in the use of 
free gymnastics, light wooden 
dumb-bells, rings, and so on. We 
learned that a daily exercise of this 
kind would do much to develop 
feeble and narrow chests, and to check the tendency 
to curvature of the spine and round shoulders so com- 
mon with school children. 

The study of physiology should do much to arouse 
the attention of teachers and pupils to the fact that 
physical culture is important and useful. The preced- 
ing sections of this book, therefore, can be utilized to 
impress upon the minds of young people the value of 
some kind of gymnastic training. 

375 




376 YOUNG folks' physiology 

For the benefit of those teachers who may wish to 
encourage their pupils to take an interest in the matter 
of physical culture, the following simple gymnastic 
exercises have been arranged. They are merely intro- 
ductory to more extended exercises. They may be 
easily abridged, extended, or modified as may be 
thought best. These exercises are not new or novel. 
They have been carefully selected and thoroughly 
tested in the schoolroom, and can be practised by any 
pupil in ordinary health without any fear of injury. 

Hints for Practice. — Gymnastic exercises should 
be practised with regularity and moderation. An exer- 
cise of fifteen or twenty minutes, once or twice a 
day, is enough. The various movements should be 
executed steadily and gradually and never in a spas- 
modic sort of way. They should be performed with 
attention, force of will, and energy. Slowly at first, 
after a time, practice will give vigor and precision. 

Avoid all exposure and draughts between and after 
the exercises. A wholesome fatigue may be felt, but 
not weariness or exhaustion. Let the practice be dis- 
continued for a time if it results in dizziness, nausea, 
and pains in the back or side. 

Do not practise too soon after eating a full meal, 
but rather one hour or more before a meal. Do not 
have the clothing too tight about the neck, chest, or 
abdomen during the exercise. 

Note. — These exercises have been compiled and rearranged from Lucy B. 
Hunt's " Handbook of Light Gymnastics" [price 50 cents], a most excellent and 
practical maunal for teachers. With the aid of this excellent little book, the 
teacher can easily arrange more extended and complicated exercises, suited to the 
special need of his own school or class. 



APPENDIX $77 



EXERCISES 
I. FREE GYMNASTICS. 

Position. — Stand with heels together, hips and 
shoulders back, hands firmly closed and well back upon 
the chest. 

Directions. — Each number fills a strain of music 
except when otherwise specified. 

Keep the heels together and hips back, unless the 
exercise otherwise directs. The arms overhead should 
always be with elbows unbent. 

These exercises should be taken slowly and with 
caution at first. As the strength increases, greater 
rapidity and force should be employed. 

Music for the free gymnastics should be either in 
galop or polka time. 

EXERCISE I. 

i. Thrust right hand down twice, left twice, alter- 
nately twice, together twice. 

2. Repeat No. I, only thrust hands out at sides in- 
stead of down. 

3. Repeat No. 1, thrusting hands directly up. 

4. Repeat No. 1, thrusting hands from shoulders 
directly forward. 

exercise 2. 

5. Right hand down once, left once, then clap hands 
through rest of the strain. 

6. Same exercise, out at sides. 

7. Same exercise, directly up. 

8. Same exercise, out in front. 



378 



YOUNG FOLKS PHYSIOLOGY 



EXERCISE 3. 

9. Hands on the hips, step with right foot forward, 
then diagonally forward, directly at side, diagonally 





Fig. 08. Fig. 99. 

back, directly back, cross back of left, cross again still 
farther back ; lastly cross in front of left foot, return- 
ing to position after each step. 

10. Repeat No. 9, with left foot. 

exercise 4. 

11. Stamp with right foot forward three times, 
advancing each time, then left three times. Stamp 
three times back with right foot, same with left. 

12. Repeat No. 11. 




APPENDIX 379 

EXERCISE 5. 

13. Hands still on hips twist body alternately to right 
and left, twice each ; four beats of music. 

14. Bend body alternate- 
ly to right and left, four 
beats of music finishing 
the strain. 

exercise 6. 

15. Bend body alternate- 
ly forward and back, twice 
each. 

16. Bend body first 
right, then back, left, 
front ; reverse, left, back, fig. 100. 
right, front, finishing the strain. 

17. Same as No. 13, only twist the head. 

18. Same as No. 14, only bend the head instead of 
the body. 

exercise 7. 

19. Same as No. 15, with head only. 

20. Like No. 16, bend head instead of body, right 
back, left, front, then reverse. 

exercise 8. 

21. Arms extended in front, bring them forcibly back 
to chest eight times. 

22. Arms again extended, raise right hand twice 
without bending the elbow, then left twice, alternately 
twice, together twice. 



SSo 



YOUNG FOLKS PHYSIOLOGY 



EXERCISE 9. 

23. Hands closed on chest, thrust down, out, up, and 
in front, twisting the arms each thrust ; repeat. 

24. Thrust hands from chest toward floor without 
bending the knees, stop on chest, then over head, 

rising on toes, and opening 
hands at each thrust, continue 
in half time through strain. 

25. Cross left foot over right, 
at same time touching fingers 
over head ; then right foot over 
left, alternately in half time 
through the strain. 

EXERCISE 10. 

26. Stamp left foot, then 
right, charge diagonally for- 
ward with right foot, bend and 
straighten right knee, at the 

same time carrying arms back from horizontal in front. 
When the arms are extended in front, the hands should 
be the width of the shoulders apart. 

27. Repeat this exercise on the left side. 




Fig. ioi. 



II. EXERCISES WITH DUMB-BELLS. 



Position. — Heels together, hips and shoulders 
back, bells down at sides. One-half of each strain of 
music is given to the exercise, the other half to what is 
called "the attitude." In taking these attitudes the 



APPENDIX 



381 



bells are brought first to the chest ; then, unless other- 
wise specified, placed upon the hips. 

Directions. — Step carefully but quickly to all the 
attitudes. 

Rest oftener than in the other exercises. 

Use too light rather than too heavy dumb-bells. 
Old-fashioned waltzes, like the " Boston Dip," are best 
for these exercises. Scotch airs, 
and airs from popular operas in 
this time, can easily be adapted 
by a skilful musician. 

EXERCISE II. 

28. Hands down at sides, palms 
in front, turn bells four times, 
bringing them to chest on fourth 
accented beat. 

Attitude: Step diagonally for- 
ward with right foot, carrying hands to hips, looking 
over right shoulder. 

29. Elbows at sides, turn bells just half-way round 
four times. 

Attitude; Step diagonally forward with left foot, 
looking over left shoulder. 

30. Arms extended at sides, turn bells four times. 
Attitude: Step diagonally back with right foot, look- 
ing over right shoulder. 

31. Arms extended over head, palms in front, turn 
bells four times. 

Attitude: Step diagonally back with left foot, looking 
over left shoulder 




382 



YOUNG FOLKS PHYSIOLOGY 



EXERCISE 12. 

32. Bells far back on chest, thrust both down, out at 
sides, up, and out in front. 

Attitude: Turn to the right, throw arms up at side 
without bending the knees. The bells in this attitude 
should be exactly horizontal and parallel. 

33. Repeat No. 32, turning to the left and throwing 
the arms up on left side. 

Attitude : Repeat attitude No. 32. 




exercise 13. 
34- Drop bells 



at 



sides, right hand up to 
armpit once, left once, 
together twice. 

Attitude: Drop to 
sitting position, bells 
touching the floor, rest 
through the remainder 
of the strain. 



exercise 14. 
35. Bells on shoul- 
ders, thrust each up 
once, both together 
twice. 



thrust 
both 

Fig. 102. 

Rise on toes, palms forward, bells parallel 



Attitude : 

36. Arms extended in front, turn four times. 

Attittide : Step diagonally forward with right foot, 
right hand on hip, looking back at left bell, which is 
extended in left hand. 



APPENDIX 383 

EXERCISE 15. 

37. Arms extended sideways at an angle of forty-five 
degrees, turn bells four times. 

Attitude: Step forward with left foot, left hand on 
hip, looking back at right bell, which is extended in 
right hand. 

exercise 16. 

38. Bells on chest, right hand down, then up, left 
hand the same. 

. Attitude: Turn body to right, thrust right hand 
obliquely up, palm up ; left hand obliquely down, palm 
down. 

EXERCISE 17. 

39- Bells on chest, right hand up, left down ; reverse, 
then both down, both up. 

Attitude: Turn to left, thrust hands up and down as 
in No. 38. 

EXERCISE l8. 

40. Arms extended in front, palms opposite, right 
hand up once, left the same, both together up twice. 

This should he done without bending the elbows. 

Attitude: Step diagonally forward with right foot, 
the body and head thrown forward, and arms thrown 
wide apart. 

41. Repeat No. 40. 

Attitude : Repeat attitude No. 40, on the left side. 

exercise 19. 

42. Arms extended at sides, right arm up once, left 
once, both twice, without bending the knees. 



3§4 



YOUNG FOLKS PHYSIOLOGY 



Attitude : Step diagonally back with right foot, right 
hand up, with bell perpendicular, left hand on hip. 
43- Repeat No. 42. 
Attitude : Repeat attitude on left side. 

EXERCISE 20. 

44. Arms extended, with bells parallel in front, bring 
the bells back forcibly upon the chest four times. 

Attitude: Fold the arms with bells closely pressed 
against the chest, and bend back slowly from the waist. 



III. EXERCISE WITH WANDS. 

Directions. — These exercises are performed in 
couples, partners facing each other about three feet 
apart ; the one standing on right 
of teacher on platform holding 
both rings. 

Schottische time is the best, 
but slow marches and quicksteps 
can be used. 

Always select a wand just long 
enough to reach the armpit when 
placed on the floor at one's side. 
All exercises from behind the 
head or back should be taken 




with caution, 
weak' backs. 



and avoided 



or 

altogether 



by those with 



Note. — For several of the illustrations in this chapter, the author 
is indebted to the publishers (Educational Publishing Company, Boston), 
for kind permission to take them from their excellent book called 
"Ladies' Home Calisthen 



APPENDIX 



385 



Position. — Heels together, hips and shoulders well 
back. The wand is held in front of the right shoulder, 
till first signal from the piano, which consists of three 
chords struck with both hands, the first being the 
length of the other two ; then drop it horizontally in 
front of the body. At second signal raise the wand till 
the arms are extended in horizontal position in front of 
body, place the hands so as to divide the wand into 
three equal parts. 
At third signal, carry 
the wand back to 
second position down 
in front. 

The simplest of 
Strauss' s waltzes 
must be used, or 
those of other com- 
posers similar in 
style. 

Directions. — In 
all exercises, turning 
back to back, be care- 
ful and not pull sud- 
denly, and never let 
go the ring before FlG io3 

the word is given. 

Always stand at such a distance from next couple 
that there can be no hitting of rings. 

The rings should always be strongly made, and about 
six inches in diameter. 




386 YOUNG. folks' physiology 

EXERCISE 21. 

45. Raise the wand to chin four times, keeping elbows 
high, last time carry it above the head, then bring down 
under chin four times. 

46. Carry wand from above the head nearly to floor, 
four times, without bending knees or elbows, then down 
back of the neck four times. 

47. Carry wand from above the head to chin, and 
then back of neck, alternately four times each. 

exercise 22. 

48. Wand over head. On first beat, carry right 
hand to right end of wand, on second beat, left hand to 
left end, then carry hand back of head to hips, six 
times, keeping elbows stiff. 

49' Carry wand back from above head down nearly 
to floor ; and then back to hips, four times, alternately 
four times each. 

50. Carry wand from above the head to right and 
left sides alternately eight times, keeping elbows stiff, 
and stopping exactly over head each time. 

EXERCISE 23. 

51. On first beat, let go wand with left hand, place 
end of wand on floor between feet. On second beat 
place wand on floor at arm's length, diagonally forward 
on right side. Step with right foot to wand through 
rest of strain, keeping right arm, left knee, and wand 
perfectly straight. 

52. Repeat No. 5 1 on left side. 



APPENDIX 



387 



53. Repeat No. 51, keeping the foot stationary, the 
knee bending with each accented beat. 
54- Repeat No. 53 on left side. 

exercise 24. 

55. Arms horizontal in front, wand held perpendicu- 
larly, bring wand back to chest eight times, keeping 
elbows high. 

56. Wand and arms in same position, bring wand to 
right and left shoulders alternately four times each. 
In passing the wand 
from one side to the 
other, raise the arms 
straight to a horizontal 
position in front. 

EXERCISE 25. 

57. Hands in front 
of chest, point wand 
diagonally forward at 
an angle of forty-five 
degrees, first to the 
right, then to the left 
alternately through 
strain, making the 
change of hands just 
in front of chin. 

58. With wand point- 
ing in the same direc- 
tion as in last exercise, step diagonally forward with 
right and left foot alternately through strain. 




Fig. 



5 5 S YOUNG folks' physiology 

59. Repeat Mo. 58, only step back instead of forward, 
leading with left foot instead of right, keeping wand 

; :-ir.:ir.g iirr^ri 

EXERCISE 26. 

60. Wand horizontal over head, right hand in front, 
reverse position, bringing left hand in front, on half 
time through strain. 

61. Same position, right face, bend forward bringing 
wand to perpendicular on right side, four times. 

62. Repeat Mo. 61 on left side. 

exercise 27. 

63. On first beat, put left end of wand on floor in 
front of feet ; on second beat, carry wand at arm's 
length in front, charge right foot to wand twice, left 
four times, changing hands and feet at same time. 

64. Right foot back four times, right hand on wand, 
same with left hand and foot. 

65. Right foot forward and back four times, left the 
same, holding wand in same position as last exercise. 

66. Both hands on wand in front, right foot forward, 
left bi:k at the same t:::;e. reverse ir.ii repeat. 



IV. EXERCISES WITH RINGS- 
EXERCISE 28. 



67. On first beat of music, the ring in right hand is 
extended, and grasped by partner's right hand. Second 
beat, right feet together, toes touching ; on third beat 
left feet back at right angles with right feet, with left 



APPENDIX 389 

hands upon hips. Turn the ring over half-way and 
then back to place through rest of strain, keeping 
perfect time. 

68. Repeat No. 67, only use left hand and left foot 
instead of right. 

69. Repeat No 67, only first join both hands, on 
second beat right feet together, third beat step back as 
before, turn rings through strain. 

70. Repeat No 69, with both 
hands joined and left feet touch- 
ing, right feet back, turn rings 
through strain. 




exercise 29. 

71. On first beat, turn back to 
back, on second beat left feet to- 
gether, charge directly forward 
with right feet ; head and shoul- 
ders well thrown back, pull evenly 
with partner, and turn the rings through strain. 

72. Repeat No. 71, with right feet together, left out 
in front, turn rings through strain. 

exercise 30. 

73. On first beat, turn face to face, on second beat 
raise arms above head, then lower rings without bend- 
ing knees, looking alternately to right and left of 
partner through strain. 

74. First beat, lift arms towards platform, high up at 
side, the others low down at the opposite side, carry 
them alternately up and down through half the strain, 
then both together, half a strain. 



390 YOUNG FOLKS PHYSIOLOGY 

EXERCISE 31, 

75. First beat, turn back to back, charge diagonally 
forward with right and left feet alternately through 
strain. 

76. First beat, turn face to face, place left foot inside 
partner's left, short step back with right foot at right 
angles with the left. Rings over head held firmly, 
arms perfectly straight, sway alternately through the 
strain. 

77. Repeat No 76, with right feet together instead 
of left. 

EXERCISE 32. 

78. First beat, turn back to back, charge up and 
down the hall alternately twice each ; charge with right 
feet at same time, then left feet at same time, alter- 
nately through rest of strain. 

79. First beat, turn face to face, repeat No. 78. 

Books for Study and Reference. — In addition to other works on 
physical culture mentioned in this book, the student will find the follow- 
ing books of much value and interest: i. Lagrange's Physiology of 
Exercise. 2. Anderson's Light Gymnastics. 3. Blaikie's How to get 
Strong. 4. Enebuske's Gymnastic Days' Orders. 5. Mara Pratt's 
New Calisthenics. 6. Mara Pratt's Supplement to New Calisthenics. 
7. Roberts's Gymnastic Exercises Classified. 8. Maclaren's Physical 
Education. 9. Ladies' Home Calisthenics. 

Reference has been made to several standard works on the Swedish 
system <*i page 65. 



GLOSSARY 



The ordinary use of a glossary is to explain, in some detail, many of the more diffi- 
cult words used in the text. The pupil will, however, find it an admirable and 
profitable review exercise, to drill himself on the spelling, derivation, and defini- 
tion of each word, mastering a few words every day. 



Ab-do'men ( Latin abdo, abdere, to 
conceal). The largest cavity of 
the body, containing the liver, 
stomach, intestines, etc. 

Ab-sor'bents (L. absorbere, to suck 
up). The vessels which take 
part in the process of absorption. 

Ab-sorp'tion. The process of suck- 
ing up nutritive or waste matters 
by the blood-vessels^ or lym- 
phatics. 

Ac-com-mo-da'tion of the Eye. 
The alteration in the shape of the 
crystalline lens, which accommo- 
dates, or adjusts, the eye for near 
and remote vision. 

Ac-e-tab'u-lum (L. acetum, vine- 
gar). A little cup used by the 
ancients for holding vinegar ; ap- 
plied, in anatomy, to the round 
cavity in which the hip-bone re- 
ceives the head of the femur. 

Ac'id (L. acidus, from acere, to be 
sour). A substance usually sour, 
sharp, or biting to the taste. 

39 



Ad'am's Ap'ple. An angular pro- 
jection of cartilage in the front of 
the neck. It is particularly prom- 
inent in males, and is so called 
from a notion that it was caused 
by the apple sticking in the 
throat of our first parent. 

Al-bu'men, or Albumin (L. albus, 
white). An animal substance re- 
sembling the white of an egg. 

Al-bu'min-oids. A class of sub- 
stances resembling albumen : they 
may be derived from either the 
animal or vegetable kingdoms. 

Al'i-ment (L.a/o, to nourish). That 
which affords nourishment ; food. 

Al-i-ment'a-ry Ca-nal (from ali- 
ment). A long tube in which the 
food is digested, or prepared for 
reception into the blood. 

Al'ka-li (Arabic, al kali, the soda 
plant). A name given to certain 
substances, such as soda, potash, 
and the like, which have thf 
power of combining with acids. 



392 



GLOSSARY 



An-ses-thet'ics (Greek an, without, 

aisthesia, feeling). Those medi- 
cinal agents which prevent the 
feeling of pain, such as chloro- 
form, ether, laughing-gas, etc. 

A-nat'o-my (Gr. anaUmno, to cut 
up). The science which de- 
scribes the structure of living 
things. 

A-or'ta (Gr. aeirein, to lift up). 
The largest artery of the body, 
arising from the left ventricle of 
the heart. The name was first 
applied to the two large branches 
of the trachea, which appear to be 
lifted up by the heart. 

A'que-ous Humor (L. aqua, 
water). The watery fluid occu- 
pying the space between the cor- 
nea and crystalline lens of the 
eye. 

A-racb/noid Mem'brane (Gr. 
arachm, a spider, and eidos, like). 
The thin covering of the brain 
and spinal cord, between the 
dura mater and the pia mater. 

Arbor Vi'tae (L.). Literally, "the 
tree of life ; " a name given to 
the peculiar appearance presented 
by a section of the cerebellum. 

Ar'ter-y i Gr. aer, air, and tereo, to 
contain). A vessel by which 
blood is carried away from the 
heart. It was supposed by the 
ancients to contain only air; 
hence the name. 

Ar-tic-u-la'tion (L. articulo, to 
form a joint). The more or less 
movable union of bones, etc. ; a 
joint. 

A-ryt'e-noid Car'ti-la-ges (Gr. 
arutaina, a ladle). Two small 



cartilages of the larynx, resem- 
bling the mouth of a pitcher. 

As-sim-i-la'tion (L. ad, to, and 
similis, like). The conversion of 
food into living tissue. 

Au'di-to-ry (L. audito, to hear) 
Nerve. One of the cranial 
nerves : it is the special nerve of 
hearing. 

Au'ri-cle (L. auricula, a little ear). 
A cavity of the heart. 

Bac-te'ria (Gr. baktron, a staff). A 
microscopic, vegetable organism ; 
certain species are active agents 
in fermentation, while others 
appear to be the cause of infec- 
tious diseases. 

Bile. The gall, or peculiar secre- 
tion of the liver ; a viscid, yellow- 
ish fluid, and very bitter to the 
taste. 

Blad'der (Saxon, bleddra, a blad- 
der, a goblet). A bag, or sac, 
serving as receptacle of some 
secreted fluid ; as the gall-bladder, 
etc. In common language, the 
receptacle of the urine in man 
and other animals. 

Bright's Disease'. A group of 
diseases of the kidney, first de- 
scribed by Dr. Bright. 

Bronch'i (Gr. bronchos, windpipe). 
The two first divisions, or 
branches, of the trachea: one 
enters each lung. 

Bronch'i-al Tubes. The smaller 
branches of the trachea within 
the substance of the lungs, ter- 
minating in the air-cells. 

Bronch-i'tis (from bronchos, and 
-itis, a suffix signifying inflam- 
mation of the larger bronchial 



GLOSSARY 



393 



tubes ; a " cold " affecting the 
lungs. 

Bun'ion. An enlargement and in- 
flammation at the first joint of 
the great toe. 

Cal'lus (L. calleo, to be thick- 
skinned). Any excessive hard- 
ness of the skin, caused by 
friction or pressure. 

Ca-nal' (L. canalis, a canal). In 
the body, any tube or passage. 

Ca'pil-la-ry (L. capillus, hair). The 
smallest blood-vessels, so called 
because they are so tiny. 

Car-bon'ic A'cid. The gas which 
is present in the air breathed out 
from the lungs ; a waste product 
of the animal kingdom, and a 
food of the vegetable kingdom. 
More correctly called Carbon Di- 
oxide. 

Car/di ac (Gr. kardia, the heart). 
The cardiac orifice of the stom- 
ach is the upper one, and is near 
the heart; hence its name. . 

Car-niv'o-rous (L. ca'ro, flesh, and 
vo'ro, to devour). Subsisting 
upon flesh. 

Car'ron Oil. A mixture of equal 
parts of linseed-oil and lime- 
water, so called because first used 
at the Carron Iron Works in 
Scotland. 

Car'ti-lage. A tough but flexible 
material, forming a part of the 
joints, air-passages, nostrils, ear ; 
gristle. 

Ca'se-ine (L. ca'seus, cheese). The 
albuminoid substance of milk : it 
forms the basis of cheese. 

Ca-tarrh'. An inflammation of a 
mucous membrane. 



Cell (L. cella, a storeroom). The 
name of the tiny microscopic ele- 
ments, which, with slender threads 
or fibres, make up most of the 
body : they were once believed to 
be little hollow chambers ; hence 
the name. 

Cem'ent. The substance which 
forms the outer part of the fang 
of a tooth. 

Cer-e-bel'lum (diminutive for cer'~ 
ebrum, the brain). The little 
brain, situated beneath the poste- 
rior third of the cerebrum. 

Cer'e-brum (L.). The brain 
proper, occupying the entire 
upper portion of the skull. It is 
nearly divided into two equal 
parts, called "hemispheres," by 
a cleft extending from before 
backward. 

Chlo'ral. A powerful drug used 
by physicians to induce sleep. 

Cho'roid (Gr. chorion, skin, and 
eidos, form). The middle coat of 
the eyeball. 

Chyle (Gr. chulos, juice). The 
milk-like fluid formed by the di- 
gestion of fatty articles of food in 
the intestines. 

Chyme (Gr. ckumos, jaice). The 
pulpy liquid formed by digestion 
in the stomach. 

Cil'i-a (pi. of cil'i-tim, an eyelash). 
Minute hair-like processes found 
upon the cells of the air-passages 
and other parts that are com- 
monly moist. 

Cir-cu-la'tion (L. cir'culus, a 
circle). The course of the blood 
through the blood-vessels of the 
body. 



394 



GLOSSARY 



Co-ag-u-la'tion (L. coag'ulo, to cur- 
dle). Applied to the process by 
which the blood clots or solidifies. 

Coch'le-a (L. coch'lea, a snail- 
shell). The spiral cavity of the 
internal ear. 

Conch'a (Gr. konche, a mussel- 
shell). The shell-shaped portion 
of the external ear. 

Con-ges'tion (L. con, together, and 
gero, to bring). An unnatural 
gathering of blood in any part of 
the body. 

Con-junc-ti'va (L. con, together, 
and jun'go, to join). A thin 
layer of mucous membrane which 
lines the eyelids, and covers the 
front of the eyeball, thus joining 
the latter to the lids. 

Con-nect'ive Tis'sue. The net- 
work which connects the minute 
parts of most of the structures of 
the body. 

Con-sti-pa'tion (L. con, together, 
and stipo, to crowd close). Cos- 
tiveness; tardiness in evacuating 
the bowels. 

Con-sump'tion (L. consumo, to 
consume.) A disease of the 
lungs, attended with a fever and 
cough, and causing a gradual 
decay of the bodily powers. The 
medical name is phthisis. 

Con-trac-til'i-ty (L. con, together, 
and tra 'ho, to draw). The prop- 
erty of a muscle which enables it 
to contract, or draw its extremi- 
ties closer together. 

Con-vo-lu'tions (L. con, together, 
and vol'vo, to roll). The tortuous 
foldings of the external surface of 
the brain. 



Con-vul'sion (L. convel'lo, to pull 
together). A more or less vio- 
lent agitation of the limbs or 

body. 

Corn (L. cor'nu, a horn). A small 
portion of the outer skin, of horn- 
like hardness. 

Cor'ne-a (L. cor'nu, a horn). The 
transparent, horn-like substance 
which covers a part of the front 
of the eyeball. 

Cor'pus-cles Blood. (L. dim. of 
cor' pus, a body). The small disks 
which give to the blood its red 
color : the white corpuscles are 
globular and larger. 

Cos-met'ic (Gr. kosmeo, to adorn). 
Applied to articles which are 
supposed to increase the beauty 
of the skin. 

Cra'ni-al (L. cra'nium, the skull). 
Pertaining to the skull. 

Cri'coid (Gr. kri'kos, a ring, and 
eidos, form). A cartilage of the 
larynx, resembling a seal-ring in 
shape. 

Crys'tal-line Lens (L. crystal' hem, 
a crystal). One of the so-called 
humors of the eye ; a double- 
convex body situated in the front 
part of the eyeball. 

Cu'ti-cle (L. dim. of cu'tis the 
skin). The scarf-skin; also 
called the cpider'mis. 

Cu'tis (Gr. skutos, a skin, or hide). 
The true skin, lying beneath the 
cuticle ; also called the der'mis. 

Dan'druff. The small scales, or 
particles, which separate from 
the scarf-skin of the scalp. 

De-cus-sa'tion (L. deats'sis, the 
Roman numeral ten, X.). A re- 



GLOSSARY 



395 



ciprocal crossing of fibres from 
side to side. 

De-gen-er-a'tion (L. degenerare, to 
grow worse; to deteriorate). A 
change in the structure of any 
organ which makes it less fit to 
perform its duty or function. 

Deg-lu-ti'tion (L. deglutire, to 
swallow down). The act, or 
process, of swallowing. 

De-lir'i-um. A state in which the 
ideas of a person are wild, irregu- 
lar, and unconnected. 

Den'tine (L. dens, dentis, a tooth). 
The hard substance which forms 
most of a tooth ; ivory. 

De-o-do-ri'zer. An agent which 
corrects any foul or unwholesome 
odor. 

Di'a-phragm (Gr. diaphrasso, to 
divide by a partition). A large, 
thin muscle which separates the 
cavity of the chest from the 
abdomen. 

Di-ar-rhce'a (Gr. diarrhein, to flow 
through). An unnaturally fre- 
quent and liquid evacuation of 
the bowels. 

Dif-fus'ion of Gases. The power 
of gases to become intimately 
mingled. 

Dis-in-fect'ant. Agents used to 
destroy the causes of infection. 

Dis-lo-ca'tion (L. dislocare, to put 
out of place). The name of an 
injury to a joint, in which the 
bones are displaced or forced out 
of their sockets. 

Dis-sec'tion (L. dis, apart, and 
seco, to cut). The cutting up of 
an animal in order to learn its 
structure. 



Duct (L. du'co, to lead). A narrow 
tube : the thoracic duct is the main 
trunk of the absorbent vessels. 

Du-o-de'num (L. duode'ni, twelve). 
The first division of the small 
intestines, about twelve fingers'- 
breadth long. 

Dys-pep'si-a (Gr. dus, ill, peptein, 
to digest). A condition of the 
alimentary canal in which it di- 
gests imperfectly. Indigestion. 

El'e-ment. One of the simplest 
parts of which anything consists. 

E-met'ic (Gr. emeo, to vomit). 
Having power to excite vomiting. 
Also, a medicine which causes 
vomiting. 

E-mul'sion (L emulgere, to milk). 
Oil in a finely divided state, sus- 
pended in water. 

En-am'el (French, email). The 
dense material which covers the 
crown of a tooth. 

En'e-ma (L. enema, a clyster). An 
injection thrown into the rectum, 
as a medicine, or to impart 
nourishment. 

Ep-i-glot'tis (Gr. epi, upon, and 
glottis, the entrance to the wind- 
pipe). A leaf-shaped piece of 
cartilage which covers the top of 
the larynx during the act of 
swallowing. 

Ep'i-lep-sy (Gr. epilepsis, a. seiz- 
ure). A nervous disease accom- 
panied by fits in which conscious- 
ness is lost. The falling sick- 
ness. 

Eu-sta'chi-an (from an Italian ana- 
tomist named Eustachi). The 
tube which leads from the throat 
to the middle ear, or tympanum. 



396 



GLOSSARY 



Ex-cre'tion (L. excer'no, to sepa- 
rate). The separation from the 
blood of the waste matters of the 
body; also, the materials ex- 
creted. 

Ex-pi-ra'tion (L. expi'ro, to breathe 
out). The act of forcing air out 
of the lungs. 

Ex-ten'sion (L. ex, out, and ten' do, 
to stretch). The act of restoring 
a limb, etc., to its natural position 
after it has been flexed, or bent ; 
the opposite oiflexio7i. 

Fau'ces. The part of the mouth 
which opens into the pharynx. 

Ferment. That which causes 
fermentation, as yeast. 

Fer-men-ta'tion (L. fermetihim, 
boiling, hot). The process of un- 
dergoing an effervescent change, 
as by the action of yeast; in a 
wider sense, the change of organ- 
ized substances into new com- 
pounds by the action of a fer- 
ment. It differs in kind according 
to the nature of the ferment 
which causes it. 

Fe'nes-tra (L.). Literally, a win- 
dow ; the opening between the 
middle and internal ear. 

Fi'bre (L.Jibra, a filament). One 
of the tiny threads of which 
many parts of the body are com- 
posed. 

Fi'brine (L. fi'bra, a fibre). An 
albuminoid substance found in 
the blood. 

Flex'ion (L flecto, to bend). The 
act of bending a limb, etc. 

Fol'li-cle (L. dim. of fol'lis, a 
money-bag). A little pouch, or 
depression, in a membrane. 



Fo-men-ta'tion (L.fo'veo, to keep 
warm). The application of any 
warm, soft medicinal subtance to 
some part of the body by which 
the vessels are relaxed. 

Fo-ra'men. A hole, or aperture. 

Fu-mi-ga'tion (L. fu'migo, to per- 
fume a place). The use of cer- 
tain fumes to counteract conta- 
gious effluvia. 

Func'tion (L. functio, a doing). 
The special duty of any organ of 
the body. 

Fun'gous Growths (L. fun'gus, a 
mushroom). A low grade of vege- 
table life. 

Gan'gli-on (Gr. ganglion, a knot). 
A knot-like swelling in a nerve ; 
a smaller nerve-centre. 

Gas 'trie (Gr. gaster, stomach). 
Pertaining to the stomach. 

Gel'a-tine (L.ge/o, to congeal). An 
animal substance which dissolves 
in hot water, and forms a jelly 
on cooling. 

Germ (L. germen, a sprout, bud). 
Disease germ; a name applied to 
certain tiny bacterial organisms 
which have been demonstrated 
to be the cause of disease. 

Gland (L. glatis, an acorn). An 
organ consisting of follicles and 
ducts, with numerous blood- 
vessels interwoven. 

Glot'tis (Gr. glotta, the tongue). 
The narrow opening between 
the vocal cords. 

Glu'ten. Literally, glue; the glu- 
tinous albuminoid ingredient of 
wheat. 

Groin. The lower part of the ab- 
domen just above each thigh. 



GLOSSARY 



397 



Gus-ta'tion (L. gusto, to taste). 
The sense of taste. 

Gus'ta-to-ry Nerve. The nerve 
of taste supplying the front part 
of the tongue, a branch of the 
" fifth " pair. 

Gym-nas'tics (Gr. gumnazo, to ex- 
ercise). The practice of athletic 
exercises. 

Hem'i-spheres (Gr. hemi, half, and 
sphaira, a sphere). Half a sphere, 
the lateral halves of the cere- 
brum, or brain proper. 

Hem'or-rhage (Gr. hat' ma, blood, 
and regnumi, to burst). Bleed- 
ing, or the loss of blood. 

He-pat'ic (Gr. hepar, the liver). 
Pertaining to the liver. 

Her-biv-o'rous (L. her'ba, an herb, 
and vo'ro, to devour). Applied 
to animals that subsist upon vege- 
table food. 

Hic'cough. A convulsive motion 
of some of the muscles used in 
breathing, accompanied by a 
shutting of the glottis. 

Hu'mor. Moisture ; the humors 
are transparent contents of the 
eyeball. 

Hy-dro-pho'bi-a (Gr. hudor, water, 
and phobeomai, to fear). A dis- 
ease caused by the bite of a rabid 
dog or other animal. 

Hy'gi-ene (Gr. hygieia, health). 
The art of preserving health, 
and preventing disease. 

In-ci'sor (L. inci'do, to cut). Ap- 
plied to the four front teeth of 
both jaws, which have sharp, cut- 
ting edges. 

In'cus. An anvil ; the name of one 
of the bones of the middle ear. 



In'di-an Hemp. The common 
name of Cannabis Indica, an in- 
toxicating drug, known as 
hasheesh, and by many other 
names, in Eastern countries. 

In-fe'ri-or Ve'na Ca'va (L.). 
Lower hollow vein; the chief 
vein of the lower part of the 
body. 

In-flam-ma'tion (L. prefix in, and 
flammo, to flame). A redness or 
swelling of any part of the body, 
with heat and pain. 

In-sal-i-va'tion (L. in, and sali'va, 
the fluid of the mouth). The 
mingling of the saliva with the 
food during the act of chewing. 

In-spi-ra'tion (L. inspi'ro, spira'- 
tum, to breathe in). The act of 
drawing in the breath. 

In-teg'u-ment (L. inte'go, to cover). 
The skin, or outer covering of 
the body. 

In-tes'tine (L. in'tus, within). The 
part of the alimentary canal 
which is continuous with the 
lower end of the stomach; also 
called the bowels. 

I'ris (L. i'ris, the rainbow). The 
thin, muscular ring which lies be- 
tween the cornea and crystalline 
lens, and which gives the eye its 
special color. 

Jaun'dice (Yr.jaunisse, yellow). A 
disorder in which the skin and 
eyes assume a yellowish color. 

Lab'y-rinth. The internal ear, so 
named from its many windings. 

Lach'ry-mal Ap-pa-ra'tus (L. 
lach'ryma, a tear). The organs 
for forming and carrying away 
the tears. 



398 



GLOSSARY 



Lac'te-als (L. lac, lac'tis, milk). 
The absorbent vessels of the 
small intestines. 

Lar'ynx. The cartilaginous tube 
situated at the top of the wind- 
pipe, or trachea; the organ of 
the voice. 

Lens. Literally, a lentil; a piece 
of transparent glass or other 
substance so shaped as either to 
converge or disperse the rays of 
light. 

Lig'a-ment (L. li'go, to bind). A 
strong, fibrous material binding 
bones or other solid parts to- 
gether : it is especially necessary 
to give strength to joints. 

Lig'a-ture (L. ligo, to bind). A 
thread of some material used in 
tying a cut or injured artery. 

Lobe. A round, projecting part 
of an organ, as of the liver, 
lungs, or brain. 

Lymph (L. lym'pha, pure water). 
The watery fluid conveyed by the 
lymphatic vessels. 

Lym-phat'ic Ves'sels. A system 
of absorbent vessels. 

Mal'le-us. Literally, the mallet; 
one of the small bones of the 
middle ear. 

Mar'row. The soft, fatty sub- 
stance contained in the central 
cavities of the bones. 

Mas-ti-ca-tion (L. mas'tico, to 
chew). The act of cutting and 
grinding the food to pieces by 
means of the teeth. 

Me-a'tus (L. meare, to wander). A 
passage or channel. 

Me-dul'la Ob-lon-ga'ta. The " ob- 
long marrow," or nervous cord, 



which is continuous with the 
spinal cord within the skull. 

Mem-bra'na Tym'pan-i. Liter- 
ally, the membrane of the drum ; 
a delicate partition separating 
the outer from the middle ear ; it 
is sometimes incorrectly called 
the drum of the ear. 

Mem'brane. A thin layer of tis- 
sue serving to cover some part of 
the body. 

Mi'cro-scope (Gr. mikros, small, 
and skopeo, to look at). An opti- 
cal instrument which assists in 
the examination of minute ob- 
jects. 

Mi'crobe (Gr. mikros, little, and 
bios, life). A microscopic organ- 
ism particularly applied to bac- 
teria. 

Mo'lar (L. mo'la, a mill). The 
name applied to the three back 
teeth at each side of the jaw; the 
grinders, or mill-like teeth. 

Mo'tor (L. mo'veo, mo'tum, to 
move). Causing motion ; the 
name of those nerves which con- 
duct to the muscles the stimulus 
which causes them to contract. 

Mu'cous Mem-brane. The thin 
layer of tissue which covers those 
internal cavities or passages which 
communicate with the external air. 

Mu'cus. The glairy fluid which is 
secreted by mucous membranes, 
serving to keep them in a moist 
condition. 

My-o'pi-a (Gr. muo, to shut, and 
ops, the eye). A defect of vision 
dependent upon an eyeball that 
is too long, rendering distant ob- 
jects indistinct; near-sight. 



GLOSSARY 



399 



Nar-cot'ic (Gr. narkoo, to be- 
numb). A medicine, which, in 
poisonous doses, produces stupor, 
convulsions, and sometimes 
death. 

Na'sal (L. na'sus, the nose). Per- 
taining to the nose. 

Nerve Cell. A minute, round, 
and ashen-gray cell found in the 
brain and other nervous centres. 

Nerve Fi'bre. An exceedingly 
slender thread of nervous tissue. 

Nos'tril (Anglo-Saxon, nosu, nose, 
and thyrl, a hole). One of the two 
outer openings of the nose. 

Nu-cle'o-lus (diminutive of nu'- 
cleus). A little nucleus. 

Nu'cle-us (L. nux, a nut). A cen- 
tral part of any body, or that 
about which matter is collected. 
In anatomy, a cell within a cell. 

Nu-tri'tion (L. nu'trio, to nourish). 
The processes by which the 
nourishment of the body is 
accomplished. 

O-don'toid (Gr. odous, a tooth, 
eidos, shape). The name of the 
bony peg of the second vertebra, 
around which the first turns. 

CE-soph'a-gus. Literally, that 
which carries food. The tube 
leading from the throat to the 
stomach ; the gullet. 

O-le-ag'i-nous (L. o'leum, oil). Of 
the nature of oil ; applied to an 
important group of food-princi- 
ples, — the fats. 

Ol-fac'to-ry (L. olfa'cio, to smell). 
Pertaining to the sense of smell. 

Op 'tic (Gr. opto, to see). Pertain- 
ing to the sense of sight. 

Or'bit (L. or'bis, a circle). The 



bony socket or cavity in which 
the eyeball is situated. 

Or'gan (L. organum, an instrument 
or implement). A portion of the 
body having some special func- 
tion or duty. 

Os'se-ous (L. os, a bone). Con- 
sisting of, or resembling, bone. 

Pal'ate (L. pala'tum, the palate). 
The roof of the mouth, consist- 
ing of the hard and soft palate. 

Pal-pi-ta'tion (L. palpitatio, a fre- 
quent or throbbing motion). A 
violent and irregular beating of 
the heart. 

Pa-pil'la. The name of the small 
elevations found on the skin and 
mucous membranes. 

Pa-ral'y-sis (Gr. paraluein, to 
loosen; also, to disable). Loss 
of function, especially of motion 
or feeling. Palsy. 

Par'a-site. A plant or animal that 
grows or lives on another. 

Pa-tel'la (L. dim. oipat'ina, a pan). 
The knee-pan. 

Pel'vis. Literally, a basin. The 
bony cavity at the lower part of 
the trunk. 

Pep'sin (Gr. pepto, to digest). The 
active principle of the gastric 
juice. • 

Per-i-car'di-um (Gr. peri, about, 
and kardia, heart). The sac en- 
closing the heart. 

Per-i-os'te-um (Gr. peri, around, 
osteon, a bone). A fibrous mem- 
brane which surrounds the bones. 

Per-i-stal'tic Move'ments (Gr. 
peri, round, and stello, to send). 
The slow, wave-like movements 
of the stomach and intestines. 



400 



GLOSSARY 



Per-i-to-ne'um (Gr. periteino, to 
stretch around). The investing 
membrane of the stomach, intes- 
tines, and other abdominal 
organs. 

Per-spi-ra'tion (L. perspi'ro, to 
breathe through). The sweat. 

Pe'trous (Gr. petra, a rock). The 
name of the hard portion of the 
temporal bone, in which is situ- 
ated the drum of the ear and 
labyrinth. 

Pha-lan'ges (Gr. phalanx, a body 
of soldiers closely arranged in 
ranks and files). The bones of 
the fingers and toes. 

Phar'ynx (Gr. pharunx, the 
throat). The cavity between 
the back of the mouth and 
gullet. 

Phys-i-ol'o-gy (Gr. phusis, nature, 
and logos, a discourse). The sci- 
ence of the functions of living, 
organized beings. 

Pi'a Ma'ter (L.). Literally, the 
tender mother ; the innermost of 
the three coverings of the brain. 
It is thin and delicate ; hence the 
name. 

Pig'ment (L. pingo, to paint). 
Coloring-matter. 

Plas'ma (Gr. plasso, to mould). 
Anything formed or moulded. 
The liquid part of the blood. 

Pleu'ra (Gr. pleura, the side, also 
a rib). A membrane covering 
the lung, and lining the chest. 

Pleu'ri-sy. An inflammation af- 
fecting the pleura. 

Pneu-mo-gas'tric (Gr. pneumon, 
the lungs, and gaster, the stom- 
ach). It is the principal nerve of 



respiration ; also called the vagus, 
or wandering nerve. 

Pneu-mo'nia. An inflammation 
affecting the air-cells of the lungs. 

Poi'son (Fr. poison). Any sub- 
stance, which, when applied ex- 
ternally, or taken into the stom- 
ach or the blood, works such a 
change in the animal economy as 
to produce disease or death. 

Por'tal Vein (L. porta, a gate). 
The venous trunk formed by the 
union of all the veins coming 
from the intestines. It carries 
the blood to the liver. 

Pres-by-o'pi-a (Gr. presbus, old, 
and ops, the eye). A defect of 
the accommodation of the eye, 
caused by the hardening of the 
crystalline lens ; the " far-sight " 
of adults and aged persons. 

Proc'ess (L. proce { 'do, processus, to 
proceed, to go forth). Any pro- 
jection from a surface ; also, a 
method of performance ; a pro- 
cedure. 

Pro'te-id (Gr. protos, first, and eidos, 
form). An element allied to ni- 
trogen ; a substance containing 
such elements; an albuminoid. 

Pty'a-lin (Gr. ptualon, saliva). The 
peculiar organic ingredient of the 
saliva. 

Pul'mo-na-ry ( L. pul'mo, pulmo- 
nis, the lungs). Pertaining to the 
lungs. 

Pulse (L, pel'lo, pul'sum, to beat). 
The striking of an artery against 
the finger, occasioned by the con- 
traction of the heart, commonly 
felt at the wrist. 

Pu'pil (L. pupil'la). The central, 



GLOSSARY 



40I 



round opening in the iris, through 
which light passes into the inte- 
rior of the eye. 

Py-lo'rus (Gr. puloros, a gate- 
keeper). The lower opening of 
the stomach, at the beginning of 
the small intestine. 

Re'flex (L. reflexus, turned back). 
The name given to involuntary 
movements produced by an exci- 
tation travelling along a sensory 
to a centre, where it is turned 
back or reflected along motor 
nerves. 

Re'nal (L. renes, the kidneys). 
Pertaining to the kidneys. 

Res-pi-ra'tion (L. respi'ro, to 
breathe frequently). The function 
of breathing, comprising two 
acts, — inspiration, or breathing 
in ; and expiration, or breathing 
out. 

Ret'i-na (L. re'te, a net). The in- 
nermost of the three tunics, or 
coats, of the eyeball, being an 
expansion of the optic nerve. 

Sac'cha-rine (L. sac'charum, 
sugar). Of the nature of sugar ; 
applied to the group of food- 
substances which embraces the 
different varieties of sugar, 
starch, and gum. 

Sa-li'va. The moisture, or fluids, 
of the mouth, secreted by the 
salivary glands. The spittle. 

Scle-rot'ic (Gr. skleros, hard). The 
tough, fibrous, outer coat of the 
eyeball. 

Se-ba'ceous (L. sebum, fat). Re- 
sembling fat; the name of the 
oily secretion by which the skin 
is kept flexible and soft. 



Se-cre'tion (L. secer'no, secre'tum, 
to separate). The process of 
separating from the blood some 
essential, important fluid; which 
fluid is also called a secretion. 

Sem-i-cir'cu-lar Ca-nals. Three 
canals in the internal ear. 

Sem-i-lu'nar (L. semi, half, luna, 
mooned). Shaped like a half- 
moon. 

Sen-sa'tion. The perception of an 
external impression by the ner- 
vous system. 

Se'rum. The clear, watery fluid 
which separates from the clot of 
the blood. 

Sock'et (L. scccus, a kind of low- 
heeled shoe). An opening into 
which anything is fitted. 

Spasm (Gr. spasmos, convulsion). 
A sudden, violent, and involun- 
tary contraction of one or more 
muscles. 

Spe'cial Sense. A sense by whrch 
we receive particular sensations, 
differing from those of general 
sensibility ; such as those of 
sight, hearing, taste, and smell. 

Sprain. An injury to the liga- 
ments or tendons about a joint. 

Sta'pes. Literally, a stirrup ; one 
of the small bones of the middle 
ear, shaped somewhat like a 
stirrup. 

Stim'u-lant (L. stimulo, to prick or 
goad on). An agent which causes 
an increase of vital activity in 
the body or any of its parts. 

Stri'a-ted (L. strio, to furnish with 
channels). Marked with fine, 
parallel lines. 

Sub-cla'vi-an Vein (L. sub, under, 



402 



GLOSSARY 



and clavis, a key). The great 
vein bringing back the blood from 
the arm and side of the head ; 
so called because it is situated 
underneath the clavicle, or collar- 
bone. 

Su-pe'ri-or Ve'na Ca'va (L. upper 
hollow vein). The great vein of 
the upper part of the body. 

Sut'ure (L. sutura, a seam). The 
union of certain bones of the 
skull by the interlocking of 
jagged edges. 

Sym-pa-thet'ic Sys'tem of 
Nerves. A double chain of 
nervous ganglia, connected by 
numerous small nerves, situated 
chiefly in front of, and on each 
side of, the spinal column. 

Symp'tom (Gr. sun, with, and 
pipto, to fall). A sign, or token, 
of disease. 

Syn-ov'i-al (Gr. sun, with, ob'n, an 
egg). The liquid which lubri- 
cates the joints; joint-oil. So 
called from its resemblance to 
the white of a raw egg. 

Sys-tem'ic. Belonging to the sys- 
tem, or body, as a whole. 

Sys'to-le (Gr. sustello, to contract). 
The contraction of the heart by 
which the blood is expelled from 
that organ. 

Tac'tile (L. tacHus, touch). Relat- 
ing to the sense of touch. 

Tar'tar. A hard crust which forms 
on the teeth, and is composed of 
salivary mucous, animal matter, 
and a compound of lime. 

Tem'po-ral (L. tern' pus, time, and 
tem'pora, the temples). Pertain- 
ing to the temples ; so called be- 



cause the hair begins to turn 
white with age in that portion of 
the scalp. 

Ten'don (L. ten'do, to stretch). 
The white, fibrous cord, or band, 
by which a muscle is attached to 
a bone ; a sinew. 

Tet'a-nus (Gr. teino, to stretch). A 
disease marked by persistent con- 
tractions of all or some of the 
voluntary muscles ; those of the 
jaw are sometimes solely affected ; 
the disorder is then termed 
locked-jaw. 

Tho'rax (Gr. thorax, a breast- 
plate). The upper cavity of the 
trunk of the body, containing the 
lungs, heart, etc. ; the chest. 

Thy'roid (Gr. thureos, a shield, and 
cidos, form). The largest of the 
cartilages of the larynx : the pro- 
jection in the front of the neck is 
called " Adam's apple." 

Tis'sue. Any substance or tex- 
ture in the body formed of vari- 
ous elements, such as cells, fibres, 
blood-vessels, etc., interwoven 
with each other. 

To-bac'co (Indian, tabaco, the tube, 
or pipe, in which the Indians 
smoked the plant). A plant used 
for smoking and chewing, and in 
snuff. It has a strong smell and 
a pungent taste. 

Tra'che-a (Gr. trachus, rough). 
The windpipe, or the largest of 
the air-passages. 

Trans-fu'sion (L. transfun'do, to 
pour from one vessel to an- 
other). The operation of inject- 
ing blood taken from one person 
into the veins of another : other 



GLOSSARY 



403 



fluids than blood are sometimes 
used. 

Trich-i'na Spi-ra'lis. (A twisted 
hair). A minute species of para- 
site, or worm, which infests the 
flesh of the hog: may be intro- 
duced into the human system by 
eating pork not thoroughly 
cooked. 

Tym'pa-num '(Gr. tumpanon, a 
drum). The cavity of the middle 
ear, resembling a drum in being 
closed by two membranes. 

U-re'a (L. urina, urine). One of 
the principal constituents of the 
urine, secreted from the blood by 
the kidneys. 

U-re'ter (Gr. ourein, to pass water). 
The excretory duct of the kid- 
neys. 

U'vu-la (L. uva, a. grape). The 
small, pendulous body attached 
to the back part of the palate. 

Var'i-cose yL. varix, a dilated 
vein). An unhealthily distended 
or enlarged vein. 

Vas'cu-lar (L. vasculum, a little 
vessel). Pertaining to, or pos- 
sessing blood or lymph vessels. 

Ve'nous (L. ve'na, a vein). Per- 
taining to, or contained within, a 
vein. 

Ven-ti-la'tion. The introduction 
of fresh air into a room or build- 
ing in such a manner as to keep 



the air within it in a pure 
condition. 

Ven'tri-cles of the Heart. The 
two largest cavities of the heart, 
situated at its apex, or point. 

Ver'te-bral Col'umn (L. ver'tebra, 
a joint). The backbone ; also 
called the spinal column and 
spine. 

Ves'ti-bule. A portion of the in- 
terior ear, communicating with 
the semicircular canals and the 
cochlea ; so called from its fan- 
cied resemblance to the vestibule, 
or porch, of a house. 

Vil'li (L. vil'lus, shaggy hair). Mi- 
nute, thread-like projections 
found upon the internal surface 
of the small intestine, giving it a 
velvety appearance. 

Vit're-ous (L. vi'trum, glass). 
Having the appearance of glass ; 
applied to the humor occupying 
the largest part of the cavity of 
the eyeball. 

Viv-i-sec'tion (L. vi'vus, alive, and 
se'co, to cut). The practice of 
operating upon living animals, 
for the purpose of studying some 
physiological process. 

Vo'cal Cords. Two elastic bands, 
or ridges, situated in the larynx ; 
the essential parts of the organ 
of voice. 



INDEX 



PAGE 

Abdomen 9, 22 

Absorption 106 

by blood-vessels 109 

by the lacteals 107 

Accidents 249, 252 

Alcohol in 266 

Achilles, Tendon of 32 

Acids, Poison from 271 

Adam's apple 144, 245 

Air, Atmospheric 148 

Changes in, from breathing . 148 

Carbonic acid in 150 

Impurities in 151 

renovation by ventilation . . 152 

Air-cells of the lungs 146 

Air-passages 144 

Air-passages, how protected . . 144 

Albumens 72 

Albuminoid substances .... 72 

Alcohol 83 

as a poison 84, 85 

in accidents and emergencies 266 

how it gets into the blood . . 139 

and bodily heat 158 

Effect of, on bones .... 40 

Effect of, on muscular strength 54 

Effect of, on physical exercise 55 

Fatty decay due to ... . 53 

Effect of, upon nervous system, 197 

Effect of, on digestion . . . 118 

Effect of, on muscles ... 53 

Effect of, upon the circulation, 138 

Effect of, upon the heart . . 140 

Effect of, upon the lungs . . 158 

Effect of, upon liver .... 120 



Alcohol, Effect of, upon blood . . 140 
Effect of, in hardship . . . 160 
Effect of, upon the skin . . 176 
Effect of, upon special senses, 233 
Effect of, upon throat and voice, 247 
Effect of, upon kidneys . . 240 
Indigestion due to . . . . 118 
Inherited craving for ... 200 
Alcoholic liquors and nervous sys- 
tem 198 

Alcoholic appetite 86 

Alcoholic liquors, a costly vice . 91 

Alcoholic liquor, Final result of . 199 

Alexis St. Martin u8 

Alimentary canal 92 

Anatomy defined 4 

Animal life 1 

Animal heat 156 

how produced 156 

how regulated 157 

and alcohol 158 

Ankle-bones 32 

Apparatus defined 5 

Appetizers 74 

Aqueous humor 226 

Arteries 126, 131 

Artificial drinks 78 

Arytenoid cartilage 245 

Asphyxia 252 

Auditory canal 216 

Auricles of the heart 129 

Backbone 23 

Baths, how and when to take them, 171 

Beer 89 

104 



Bile 



405 



406 



INDEX 



PAGE 

Bile, Uses of 105 

Bladder, Gall 105 

Bleeding 263 

Bleeding, how stopped .... 263 

Bleeding from stomach and lungs . 265 

Blood 12, 122 

Circulation of . . . . 126, 134 

Coagulation of 125 

corpuscles, Red 123 

corpuscles, White . . . . 125 

Total quantity of 123 

Blood, Uses of the 122 

Blood-vessels connected with heart 131 

Body, minute structure of . . . 7 

General build of 8 

compared to locomotive . . 2 

and its nervous system ... 2 

Elements in the 8 

Bony levers of the .... 48 

Wear and tear of 72 

Bone, how made up 14 

General structure of ... . 15 

Minute structure of ... . 16 

Resistance of, to decay ... 16 

Bones, Hints about health of . . 38 

Broken 257 

how joined 35 

Effect of alcohol and tobacco on, 40 

how tied together 37 

Repair of 34 

Uses of 33 

Different shapes of ... . 16 

Bony Framework 13 

Bowels, Care of the 115 

Brain 181 

Principal masses of . . . . 181 

Breathing ......... 142 

Act of 148 

Breathe, How we 147 

Why we 142 

Bronchial tubes 144 

Bronchi 144 



PAGE 

Bruises, how treated 266 

Burns 259 

Capillaries 133 

Carbonic acid 152 

exhaled from the lungs . . . 152 

in the air 153 

Cardiac orifice 102 

Carpal bones 29 

Cartilage 245 

Arytenoid 245 

Cricoid 245 

Thyroid 245 

Cells 7 

Cement of teeth 94 

Cerebellum 183 

Cerebrum 181 

Chest 22 

Chewing of the food 93 

Chloral 208 

Chocolate 79 

Chyle 106 

Chyme 104 

Cider 87 

Cilia . 145 

Circulation, General Plan of . . 126 

of the blood 134 

Rapidity of 137 

through the heart .... 135 

through the lungs .... 135 

Clavicle 28 

Clot 125 

Clothing, Why we need .... 173 

Hints on use of 174 

Coagulation of the blood .... 125 

Coccyx 24 

Cocoa 79 

Coffee 79 

Effects of 80 

Constipation 115 

Collar-bone 28 

Color-blindness 230 

Column, Spinal 24 



INDEX 



407 



PAGE 

Conjunctiva 229 

Contraction of muscles .... 45 

Convulsions 252 

Cooking food 116 

Cords, Vocal 144, 247 

Cornea 223 

Corpuscles, Blood 123 

Cranial nerves 184 

Cranium, Bones in 19 

Cricoid cartilage 245 

Crystalline lens 225 

Cuticle 161 

Cutis 161 

Decay, a law of Nature .... 81 

Cause of 82 

Decussation of motor and sensory 

fibres of spinal cord ... 24 

Dentine 

Development, Physical, Importance 

of 62 

Diaphragm 9, 23 

Movements of the, in respira- 
tion 149 

Diet, Different articles of . . . 75 

Digestion 11, 92 

General plan of 92 

Gastric 102 

Intestinal 104 

Disinfectants, what to use . . . 275 

How to use 276 

Disinfection 274 

Distillation 90 

Distilled liquors 90 

Drinks, Artificial 78 

Fermented 11 

Drowning 253 

Duct, Biliary 104 

Pancreatic 104 

Tear 230 

Thoracic 107 

Duodenum 104 

Dura Mater 183 



PAGE 

Ear 216 

Outer .216 

Inner 218 

Middle 216 

Care of the 220 

Bones of the 216 

Elements in the body 8 

Emergencies 249, 252 

Emulsion of fats in digestion . . 104 

Enamel of the teeth 94 

Epiglottis 99, 144 

Epileptic fits 252 

Ethmoid bone 20 

Eustachian tube 217 

Excretion 12, 98, 235 

Organs of 237 

Exercise, Physical, effect of . . 57 

Amount of 58 

Different kinds of ... . 59 
Physical, in schools . . . 11, 61 

in school education .... 62 

Time for eg 

why we need it 56 

Experiments, Practical .... 280 

Why we should make . . . 280 

Importance of making . . . 280 

General Plan of making . . 281 

on bones 285 

on skeleton 282 

with muscles 289 

on food and drink .... 291 

on digestion 303 

on heart and the circulation . 310 

on lungs and breathing . . . 314 

on the skin 316 

on the nervous system . . . 317 

on special senses 320 

on throat and voice .... 325 

on matters of every-day health 327 

Expiration 148 

Movements of 150 

Extra foods 74 



408 



INDEX 



PAGE 

Eye 222 

Muscles of 229 

Coats of the 223 

Inside of the 224 

Eye, Care of the 232 

Eyebrows 229 

Eyelashes 229 

Eyelids 229 

Face, Bones in the 20 

Fainting 252 

Far-sight 232 

Fats 74 

Fermentation 82 

Ferments 83 

Femur 31 

Fibres 7 

Fibrine of the blood 125 

Fibula 31 

Fontanelles 21 

Fomentations 251 

Food 11 

why we need it 71 

Vegetable 75 

Animal 75 

Mineral 76 

how it is swallowed .... 99 

how much to eat 1 1 1 

what to eat 112 

Proper Cooking of . . . . 116 

when to eat 113 

how to eat 114 

Foods, Classes of 72 

Nitrogenous 72 

Mineral 74 

Extra 74 

Fatty 74 

Starchy 72 

Foot 32 

Foot and hand compared ... 33 

Foreign bodies in throat .... 260 

in nose 260 

Foreign bodies in eye 261 



PAGE 

Foreign bodies in ear 261 

Framework, Bony 13 

Frontal bone 20 

Frost-bite 259 

Function defined 6 

Gall-bladder 104 

Gastric juice 102 

Action of 102 

Gland, Thymus 109 

Thyroid 109 

Glands 92, 98 

Oil 167 

Salivary 97 

Sweat 168 

Parotid 97 

Submaxillary 97 

Sublingual 97 

Lymphatic 106, 109 

Glottis 144 

Gullet 101 

Gymnastics, Various systems of . 63 

Swedish system of ... . 63 

German system of ... . 66 

System needed 67 

Gymnasium, Modern. Benefits from 66 

Hair 165 

Hand, The 29 

Hand and foot compared .... 33 

Head 17 

Bones of, how joined ... 22 

Health and strength contrasted . 58 

Hearing, Sense of 214 

Heart 127 

Beating of the 137 

Blood-vessels connected with . 131 

Effect of tobacco upon . . . 141 

Circulation through the . . 134 

Sounds of the 137 

Valves of the 129 

Work done by the .... 129 

Heat, Bodily 156 

Heat and alcohol 158 



INDEX 



409 



PAGE 

Heatstroke 256 

Humerus 29 

Hemorrhage 263 

Hips 27 

Humor, Aqueous 226 

Crystalline lens 225 

Vitreous ,. . . 226 

Hygiene defined 4 

Hyoid bone 27 

Ice-water 79 

Injured person, How to carry . . 257 

Inorganic foods 74 

Inspiration 148 

Movements of 149 

Intestinal digestion 104 

juice 105 

Intestine, Large no 

Small 104 

Intestines 104 

Villi of the 107 

Iris 224 

Jaw-bone, Upper 21 

Lower 21 

Joint between skull and spine . . 26 

between bones of the head . . 22 

Joints 35 

Kinds of 35 

Juice, Gastric 102 

Intestinal 105 

Pancreatic 105 

Kidneys 237 

Health of 239 

Effect of alcohol upon . . . 240 

Knee-pan 31 

Lachrymal bone 21 

Lacteals 106 

Absorption by 107 

Larynx i 44> 246 

Lens, Crystalline 225 

Levers, Bony, of the body ... 48 

Classes of, in the body ... 49 

Ligaments „ 37 



PAGB 

Limbs, Upper 27 

Lower 30 

Lime in the bones 14 

Liver 104 

Effects of alcohol upon ... 120 

Locomotive, Body compared to . 2 

Lungs 145 

Structure of 145 

Lungs, Effect of alcohol upon . . 158 

Lymph 109 

Lymphatic vessels . . . . 106, 109 

Malar bone 21 

Marrow of the bones 15 

Mastication 94 

Medulla oblongata 184 

Metacarpal bones 29 

Metatarsal bones ^ 

Mineral foods 74 

Mouth 94 

Muscles n>42 

Structure of 42 

how they act 43 

Kinds of 45 

Arrangement of 45 

Important 50 

Effect of alcohol on ... . 53 

Effect of tobacco on ... . 55 

Origin of 45 

Insertion of 45 

Muscular strength, Effect of alco- 
hol on 54 

Nails 166 

Care of the 167 

Narcotics 197 

Narcotics and other drugs . . . 209 

Nasal bone 21 

Near-sight 231 

Nerve, Auditory 219 

Optic 229 

Nerves 180 

Cranial 184 

Spinal ........ 188 



4io 



INDEX 



PAGE 

Nerves, sensory, Function of the . 189 

motor, Function of the . . . 189 

Sympathetic system of . . . 190 

Nerve tissue 180 

Nervous system 12, 177 

and the body 2 

compared to telegraph system 178 

Two distinct parts of ... 179 

Health of the 191 

Abuse of the 193 

Effect of alcohol upon . . . 197 

Effect of alcoholic liquors upon 198 

Final result of alcohol upon . 199 
Effect of inherited craving for 

alcohol . 200 

and alcoholic excess .... 200 

Nitrogenous foods 72 

Nose, Foreign bodies in ... . 260 

Nostrils 144 

Occipital bone 20 

Oils and fats 74 

Oil-glands ......... 167 

Opium 205 

Practical hints about . . . 207 

Organ defined 5 

Organs, vital 6 

Palate bones 21 

Palpitation of the heart .... 137 

Pancreas 105 

Pancreatic juice 105 

Papillae 213 

Parietal bones 20 

Patella . 31 

Pelvis 27 

Pepsin 102 

Periosteum 16 

Peristaltic action of the stomach 45, 102 

Perspiration, Uses of 157 

Phalanges ........ 3°; 33 

Pharynx 99, 244 

Physiology defined 4 

Pleura 146 



PAGE 

Poisons, their antidotes .... 270 

Poisons, Narcotic 86, 273 

Poisons, Different kinds of . . . 271 

Acid 271 

Metallic 272 

Other 274 

Poultices 249 

Pulmonary veins 131 

artery 131 

Pulse 138 

Pupil of eye 224 

Pylorus ., . . 102 

Questions, Test, for review . . . 331 

Radius 29 

Reflex action 186 

Importance of 187 

Respiration 12, 151 

Change of air in 151 

Movements of 151 

Object of 143 

Organs of 144, 145 

Retina 224 

Ribs 25 

Movements of, in respiration . 149 

True, false, floating .... 26 

Sacrum 24 

Saliva 96 

Mixing food with .... 96 

Salivary glands 97 

Salt, Value of 77 

Scapula 28 

Schoolrooms, Ventilation of . . 155 

Secretion 98 

Sensation 210 

Sense of hearing 214 

of sight 222 

of smell 214 

of taste 212 

of touch 212 

Sense, Muscular 211 

Senses, Special 211 

Serum 125 



INDEX 



4JI 



PAGE 

Sick-room, Hints for 267 

Sight, Sense of . 222 

Skeleton 9, 11, 13, 18 

Review analysis of ... . 41 

Skin 12, 161 

Scarf 161 

True 162 

Absorption from the . . . 164 

Care of the 169 

Effect of alcohol upon . . . 176 

Skull 19 

Skull and spine, how joined . . 26 

Sleep, Necessity for 199 

amount required 196 

Smell, Sense of 214 

Special senses 12,211 

Speech, Organ of 245 

Sphenoid bone 20 

Spinal cord 184 

Decussation of the .... 189 

Spinal nerves 188 

Spine 23 

Spleen 109 

Starches and sugars 73 

their change into sugar ... 99 

Sternum 26 

Stomach , 101 

Digestion 101 

Effects of alcohol upon . . 118 

Walls of 102 

Study, General plan of ... . 11 

Suffocation 252 

Sugars 73 

Sunstroke 256 

Sutures 19, 22 

Sweat-glands 168 

Sympathetic system of nerves 180, 190 

System defined 5 

Tarsal bones 32 

Taste, Organ of 212 

Taste, Sense of 212 

Tea 79 



PAGE 

Tea, Effect of 80 

Tear-duct 230 

Tears 230 

Teeth 94 

Temporary set of 95 

Permanent set of 95 

Bicuspids 96 

Canine 96 

Incisor 96 

Molar 96 

Wisdom 96 

Care of 117 

Temperature of the body . . . . 156 

of our living rooms . . . . 157 

Temporal bones 20 

Tendon of Achilles 32 

Tendons 47 

Thoracic duct 108 

Thorax 22 

Throat 12, 243 

Care of the 244 

Foreign bodies in 260 

Thyroid cartilage 109 

Tibia 31 

Tissues defined 6 

Tobacco 201 

Effect of, upon bones ... 40 

Effect of, upon muscles . . 53 

Effect of, upon digestion . . 121 

Effect of, upon heart . . . 141 

Effect of, upon skin . . . . 176 
Effect of, upon throat and 

voice 247 

Effect of, from moral point of 

view 204 

Evil effects of 203 

Tongue 212 

Touch, Sense of 212 

Trachea 144 

Trunk 22 

Bones in the 22 

Turbinated bones 21 



412 



INDEX 



PAGE 

Tympanum of the ear 216 

Membrane of 219 

Ulna 29 

Urine 239 

Valves of the heart 129 

of the veins 132 

Valves, Tricuspid 130 

Mitral 130 

Semilunar 130 

Veins 126, 132 

Veins compared to a sewer system 

127, 133 

Valves of 132 

Ventilation 154 

of schoolrooms 155 

Ventricles of the heart .... 129 

Vertebrae 23 

Villi of the intestines 107 

Absorption by 107 



PAGK 

Vision, Mechanism of 226 

Vitreous humor 226 

Vocal cords 144, 247 

Voice 12, 247 

Effect of alcohol and tobacco 

upon 248 

Organ of 246 

Quality of 247 

Vomer 21 

Warm, Why the body is . . . . 156 

Waste matters, Getting rid of . . 235 

Principal 235 

Water 76 

Wear and tear 72 

Windpipe 144 

Wine 88 

Work, waste, and repair .... 70 

Wounds, cut and torn 266 

Wrist 30 



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